Quiz about untitled

Question 1

Accepted Answer

B

Answer

A

Answer

C

Answer

D

Answer

E

Question 2

Nate wants to conduct an experiment to see why his goldfish keep dying. In each group he has ten fish. In group 1 he has a control group where he feeds them as normal. In the group he feeds them less than normal and in group three more than normal. He measures for the fish to die to see which tank had the largest mean survival. Which is NOT a confounding variable?

Accepted Answer

The amount of food

Answer

The pH of the tank

Answer

The age of the fish at the beginning of the experiment

Answer

Where the tank is placed

Question 3

Jill conducts an experiment to test the growth of plants in relation to the amount of sunlight they get. Each plant receives the same amount of water. One group of plants is placed directly in the sun. One group is placed partially in the sun. The last group is placed inside, with very little sun. She records the growth after each week in inches. What is the experimental variable in this experiment?

Accepted Answer

The amount of sun

Answer

The amount of water

Answer

The average growth each week in inches

Answer

The average amount of plants grown

Question 4

Jim conducts an experiment to see which type of battery lasts the longest. He gathers 30 of the same flashlights and randomly separates them into groups of ten. Type A is placed in one group of flashlights, Type B is placed in another group, and type c in the final group. He records the average amount of time the flashlight stays on for. What is the response variable in this experiment?

Accepted Answer

The amount of time the flashlight stays on

Answer

The intensity of the light

Answer

The type of battery used

Answer

The type of flashlight used

Question 5

What are some of the properties of a well designed experiment?

I. Comparison of at least two groups

II. Random assignment of treatments

III. Completely eliminate all confounding variables that could exist

Accepted Answer

I and II

Answer

I, II, and III

Answer

I and III

Answer

II only

Question 6

Can watching a documentary lead to an increase in pulse rate? The researchers had 100 volunteers record their pulse rate, then they all watched an hour long documentary about whales and after finishing the documentary they each recorded their pulse rates again. In what way is experimentation implemented in the research conducted?

Accepted Answer

None of these

Answer

Placebo

Answer

Blinding

Answer

Control group

Question 7

Which of the following is a positive benefit to use a random sample for the purpose of an observational study?

Accepted Answer

Results of the study could be generalized to the population of the study

Answer

The results of the study can be generalized to only a small certain population

Answer

Easier to conduct the experiment

Answer

Could cover many many types of different subjects

Question 8

A case of randomized block design where an experiment has two treatment conditions. The subjects are grouped together into pairs based on an equivalent variable. In each pair, one of the subjects is randomly assigned to one treatment and automatically the other subject is assigned to the other.

Accepted Answer

Matched Pairs

Answer

Placebo

Answer

Voluntary Response Bias

Answer

Cluster Random Sample

Question 9

What is a Cluster Sample?

Accepted Answer

The entire population is divided into heterogeneous groups called clusters.

Answer

Method of sampling which involves division of a population into smaller groups known as strata.

Answer

Where participants choose if they want to be in the sample or not

Answer

When a sample is chosen in a non-random way which is readily available.

Question 10

Walmart has 400 employees located at its main store in Morrisville meanwhile a Walmart on the outskirts of the state only has 100 employees. A random sample of 40 employees will be taken to be asked about how they feel about the benefits given to Walmart employees. What is the advantage of using a stratified random sampling where the strata would be the two different locations instead of using a simple random sample?

Accepted Answer

The stratified random sample would make sure that both locations of Walmart would be represented

Answer

There is no advantage

Answer

The stratified random sampling is proven to be 2x more accurate than simple random sample in every situation

Answer

Stratified random sampling is cheaper to implement

Question 11

Another word for average is

Accepted Answer

mean

Answer

sample

Answer

data

Answer

numerical data

Question 12

To test a claim about a mean, when the population standard deviation is unknown we use:

Accepted Answer

t procedures

Answer

z procedures

Answer

Pythagorean Theorem

Answer

np > 10 and n(1-p) > 10

Question 13

What does it mean when a test is statistically significant?

Accepted Answer

the test statistic had a P-value lower than the alpha level

Answer

it has reached alpha level status

Answer

the test statistic had a P-value higher than the alpha level

Answer

it is important in practical terms

Question 14

Simple random samples are taken from two large populations, designated Population 1 and Population 2. Which of the following describes a situation in which the conditions for performing a two-sample t-test for the difference of two means for these populations have not been satisfied?

Accepted Answer

n₁ = 15, n₂= 15. The distribution of Sample 1 is symmetric and unimodal with no outliers, and the distribution of Sample 2 is skewed left with no outliers.

Answer

n₁ = 15, n₂= 100. The distribution of Sample 1 is symmetric and unimodal with no outliers, and the distribution of sample 2 is skewed left.

Answer

n₁ = 15, n₂= 15. The distributions of both samples are symmetric and unimodal with no outliers.

Answer

Sample size is irrelevant in
T-procedures.

Question 15

If a level of confidence increases from 90% to 95%, which of the 4 statements given are true?
I) The margin of error increases
II) The margin of error decreases
III) The interval width increases
IV) The interval width decreases

Accepted Answer

C) I and III

Answer

A) I only

Answer

B) II and IV

Answer

D) II and III

Question 16

Researchers randomly select rats to complete at timed maze and collected 23 times (in seconds) with an average time of 55.6 second and a standard deviation of 2.3 seconds.
Which of the following statements is true?

Accepted Answer

B) We must assume the distribution is nearly normal with no outliers because the sample size is not large enough

Answer

A) We must assume that the samples are independent.

Answer

C) The 10% condition is not met.

Answer

D) The distribution is normal because the sample size is large enough.

Question 17

Question 17.

Accepted Answer

B) 10% Condition

Answer

A) Randomization Condition

Answer

C) Independent Samples Condition

Answer

D) Nearly Normal Distribution Condition

Question 18

Question 18.

Accepted Answer

D) Ho: The mean number of days 12th grade students absent is equal to the mean number of days 9th grade students are absent.
Ha: The mean number of days 12th grade students absent is less than the mean number of days 9th grade students are absent.

Answer

A) Ho: The mean number of days 9th grade students absent is equal to the mean number of days 12th grade students are absent.
Ha: The mean number of days 9th grade students absent is less than the mean number of days 12th grade students are absent.

Answer

B) Ho: The mean number of days 12th grade students absent is less than the mean number of days 9th grade students are absent.
Ha: The mean number of days 12th grade students absent is equal to the mean number of days 9th grade students are absent.

Answer

C) Ho: The mean number of days 12th grade students absent is equal to the mean number of days 9th grade students are absent.
Ha: The mean number of days 9th grade students absent is greater than the mean number of days 12th grade students are absent.

Question 19

Question 19.

Accepted Answer

A) Reject the Ho, so 12th grade seniors have a significantly lower mean number of absences than 9th grade freshman.

Answer

B) Fail to reject the Ho, so 12th grade seniors have a significantly lower mean number of absences than 9th grade freshman.

Answer

C) Reject the Ho, so there is no significant difference between 12th grade and 9th grade absences.

Answer

D) Fail to reject the Ho, so there is no significant difference between 12th grade and 9th grade absences.

Question 20

Jorge's score on Exam 1 in his statistics class was at the 64th percentile of the scores for all students. His score falls

Accepted Answer

between the median and the third quartile

Answer

between the minimum and the first quartile

Answer

between the first quartile and the median

Answer

between the third quartile and the maximum

Question 21

When Sam goes to a restaurant, he always tips the server $2 plus 10% of the cost of the meal. If Sam's distribution of meal costs has a mean of $9 and a standard deviation of $3, what are the mean and standard deviation of the distribution of tips?

Accepted Answer

$2.90, $0.30

Answer

$2.90, $2.30

Answer

$11.00, $2.00

Answer

$2.00, $0.90

Question 22

Scores on the ACT college entrance exam follow a bell-shaped distribution with mean 18 and standard deviation 6. Wayne's standardized score on the ACT was -0.5. What was Wayne's actual ACT score.

Accepted Answer

15

Answer

5.5

Answer

12

Answer

17.5

Question 23

George has an average bowling score of 180 and bowls in a league where the average for all bowlers is 150 and the standard deviation is 20. Bill has an average bowling score of 190 and bowls in a league where the average is 160 and the standard deviation is 15. Who ranks higher in his own league, George or Bill?

Accepted Answer

Bill, because his standardized score is higher than George's.

Answer

Bill, because his 190 is higher than George's 180.

Answer

Bill and George have the same rank in their league because both are 30 pins above the mean.

Answer

George, because his standardized score is higher than Bill's.

Question 24

What is the interquartile range for the distribution of absences as shown in the cumulative relative frequency graph?

Accepted Answer

3

Answer

1

Answer

2

Answer

5

Question 25

Two measures of center are marked on the density curve shown. Which of the following is correct?

Accepted Answer

The median is at the red line and the mean is at the yellow line

Answer

The median is at the yellow line and the mean is at the red line

Answer

The mode is at the red line and the median is at the yellow line

Answer

The mode is at the yellow line and the median is at the red line

Question 26

The weights of laboratory cockroaches follows a Normal distribution with mean 80 grams and standard deviation 2 grams. The following figure is the Normal curve for the distribution of weights.
Point C on the Normal curve corresponds to

Accepted Answer

78 grams

Answer

84 grams

Answer

74 grams

Answer

82 grams

Question 27

The weights of laboratory cockroaches follows a Normal distribution with mean 80 grams and standard deviation 2 grams. About what percent of the cockroaches will have weights between 76 and 84 grams?

Accepted Answer

95%

Answer

99.7%

Answer

68%

Answer

34%

Question 28

The weights of laboratory cockroaches follows a Normal distribution with mean 80 grams and standard deviation 2 grams. About what proportion of cockroaches will have weights greater than 83 grams?

Accepted Answer

0.0668

Answer

0.0228

Answer

0.1587

Answer

0.0772

Question 29

A different species of cockroaches has weights that follow a Normal distribution with a mean of 50 grams. After measuring the weights of many of these cockroaches, a lab assistant reports that 14% of the cockroaches weigh more than 55 grams. Based on this report, what is the approximate standard deviation of weights for this species of cockroaches?

Accepted Answer

4.6

Answer

14.0

Answer

5.0

Answer

6.2

Question 30

Many professional schools require applicants to take a standardized test. Suppose that 1000 students take such a test. Several weeks after the test, Pete receives his score report: he got a 63, which placed him at the 73rd percentile. This means that

Accepted Answer

Pete did better than about 73% of the test takers.

Answer

Pete did worse than about 63% of the test takers.

Answer

Pere did worse than about 73% of the test takers.

Answer

Pete did better than about 63% of the test takers.

Question 31

For the Normal distribution shown, the standard deviation is closest to

Accepted Answer

3

Answer

1

Answer

2

Answer

5

Question 32

Rainwater was collected in water collectors at 30 different sites near an industrial complex, and the amount of acidity (pH level) was measured. The mean and standard deviation of the values are 4.60 and 1.10, respectively. When the pH meter was recalibrated back at the laboratory, it was found to be in error. The error can be corrected by adding 0.1 pH units to all of the values and then multiplying the result by 1.2. The mean and standard deviation of the corrected pH measurements are

Accepted Answer

5.64, 1.32

Answer

5.64, 1.44

Answer

5.40, 1.44

Answer

5.40, 1.32

Question 33

If the heights of a populations follow a Normal distribution, and the middle 99.7% have heights between 5'0" and 7'0", what is your estimate of the standard deviation of the heights in the population?

Accepted Answer

4"

Answer

1"

Answer

3"

Answer

6"

Question 34

Until the scale changed in 1995, SAT scores were based on a scale set many years ago. For Math scores, the mean under the old scale in the 1990s was 470 and the standard deviation was 110. In 2013, the mean was 515 and the standard deviation was 116.

What is the standardized score for a student who scored 500 on the old SAT scale?

Accepted Answer

0.27

Answer

-0.27

Answer

-0.13

Answer

0.13

Question 35

Until the scale changed in 1995, SAT scores were based on a scale set many years ago. For Math scores, the mean under the old scale in the 1990s was 470 and the standard deviation was 110. In 2013, the mean was 515 and the standard deviation was 116.
Gina took the SAT in 1994 and scored 500. Her cousin Colleen took the SAT in 2013 and scored 530. Who did better on the exam, and how can you tell?

Accepted Answer

Gina - her standardized score is higher than Colleen's

Answer

Colleen - she scored 30 points higher than Gina

Answer

Colleen - her standardized score is higher than Gina's

Answer

Gina - the standard deviation was bigger in 2013

Question 36

The mean number of points per game scored by basketball players during a high school championship is 9.4, and the standard deviation is 1.5. Assuming that the number of points are normally distributed, what number of points per game will place a player in the top 15% players taking part in the basketball championship?

Accepted Answer

10.96

Answer

7.84

Answer

9.93

Answer

12.56

Question 37

The heights of 100 students are normally distributed with a mean of 172cm. What is the standard deviation of the heights given that the probability of a height above 180cm is 0.25?

Accepted Answer

11.9 cm

Answer

8 cm

Answer

9.2 cm

Answer

10 cm

Question 38

A population of bolts has a mean thickness of 20 millimeters with a standard deviation of 0.01 millimeters. Give in millimeters, a minimum and a maximum thickness that includes 68% of the population of bolts.

Accepted Answer

19.99 mm to 20.01 mm

Answer

19 mm to 21 mm

Answer

19.98 mm to 20.02 mm

Answer

19.97 mm to 20.03 mm

Question 39

To the nearest whole number, what percentile is associated with z = -.67?

Accepted Answer

25th

Answer

10th

Answer

40th

Answer

75th

Question 40

For a normal distribution with mean 480 and standard deviation 32, find the values for Q1, median, and Q3.

Accepted Answer

458, 480, 502

Answer

502, 458, 480

Answer

400, 500, 600

Answer

Cannot be determined

Question 41

The distances male long jumpers for State College jump are approximately normal with a mean of 263 inches and a standard deviation of 14 inches.
What is the probability the next male long jumper from State College jumps longer than 270 inches?

Accepted Answer

0.3085

Answer

0.1888

Answer

0.8035

Answer

0.3585

Question 42

According to the portion of the frequency table given, how many people have an MBA?

Accepted Answer

20

Answer

9

Answer

60

Answer

not enough information

Question 43

The mean weight of an adult female beagle is 28 pounds with a standard deviation of 3 pounds.  The mean weight of an adult female boxer is 70 pounds with a standard deviation of 6 pounds.  A beagle named Suzie weighs 34 pounds.  How much would a female boxer have to weigh in order for her to have the same z-score as Suzie?

Accepted Answer

82 pounds

Answer

70 pounds

Answer

76 pounds

Answer

80 pounds

Question 44

Which of the distributions displayed in the dot plots below has the highest standard deviation?

Accepted Answer

Distribution A

Answer

Distribution B

Answer

Distribution C

Question 45

According to the 1.5 x IQR rule, how many outliers are there in the data set 72, 110, 114, 115, 118, 123, 144, 156?

Accepted Answer

One

Answer

None

Answer

Two

Answer

Three

Question 46

An adult male aged 20-29 who is 73 inches tall would be shorter than what percent of males in his age group?

Accepted Answer

10%

Answer

15%

Answer

85%

Answer

90%

Question 47

In a survey of men in the United States (ages 20-29), the mean height was 69.6 inches with a standard deviation of 3.0 inches. Find the minimum height in the top 22%.

Accepted Answer

71.92 in

Answer

69.37 in

Answer

67.58 in

Answer

73.12 in

Question 48

What is the equation of the LSRL

Accepted Answer

y-hat = 3.367 - 0.062x

Answer

y-hat = 3.3 - 0.6x

Answer

y-hat = -0.062 + 3.3x

Answer

y-hat = 3.3 + 3.3x

Question 49

The correlation coefficient for the relationship between number of hours per week spent working at an off campus job and overall gpa for 125 college students was -0.64. What percent of the variation in gpa can be explained by the linear relationship between  number of hours and gpa?

Accepted Answer

41%

Answer

80%

Answer

-80%

Answer

-41%

Question 50

The equation of the least squares regression line for a set of points in a scatterplot is given above. The point (5, 7) is one point on this scatterplot. Which of the following is the residual for the point (5, 7)?

Accepted Answer

0.75

Answer

6.25

Answer

4.05

Answer

0.71

Answer

7.87

Question 51

Is the following question statistical or non statistical?

How many siblings does each Longview student have?

Accepted Answer

Statistical

Answer

Non Statistical

Question 52

Is the following question statistical or non statistical?
How many ceiling tiles are in our classroom?

Accepted Answer

Non Statistical

Answer

Statistical

Question 53

What is the median?

Accepted Answer

62

Answer

58

Answer

66

Answer

60

Question 54

Is the following question statistical or non statistical?
How many ceiling tiles are in our classroom?

Accepted Answer

Non Statistical

Answer

Statistical

Question 55

What value is the lower quartile?

Accepted Answer

60

Answer

66

Answer

58

Answer

64

Question 56

Which interval has the highest frequency?

Accepted Answer

3-4 Books

Answer

9 - 10 books

Answer

7-8 Books

Answer

5-6 Books

Question 57

Describe the shape of the graph.

Accepted Answer

Symmetrical

Answer

Skewed right

Answer

Skewed left

Answer

Random

Question 58

What is the interquartile range (IQR) of this data?

Accepted Answer

8

Answer

7

Answer

12

Answer

13

Question 59

In testing hypotheses, which of the following would be strong evidence against the null hypothesis?

Accepted Answer

obtaining data with a small p-value

Answer

using a small level of significance

Answer

using a large level of significance

Answer

obtaining data with a low test statistic

Question 60

A P-value indicates:

Accepted Answer

the probability of obtaining the results (or one more extreme) if the null hypothesis is true

Answer

the probability that the null hypothesis is true

Answer

the probability that the alternative hypothesis is true

Answer

probability of a Type I error

Question 61

Suppose the P-value for a hypothesis test is 0.0304. Using a = 0.05, what is the appropriate conclusion?

Accepted Answer

a) Reject the null hypothesis

Answer

b) Reject the alternative hypothesis

Answer

c) Fail to reject the null hypothesis

Answer

d) Fail to reject the alternative hypothesis

Question 62

When p-value is greater than alpha we:

Accepted Answer

Fail to reject Ho

Answer

Reject Ho

Answer

Fail to reject Ha

Answer

Reject Ha

Question 63

A large-scale study found that 42% of Americans play video games. A random sample of 1100 teenagers were asked whether they play games online; 575 said they did. Is there sufficient evidence to suggest that the proportion of teens who play video games is different from the national figure? Use a 5% level of significance.

Which is the correct p-value for this test?

Accepted Answer

5.08 x 10 ^-12

Answer

2.84 x 10 ^-91

Answer

2.56 x 10 ^-12

Answer

0

Question 64

A large-scale study found that 42% of Americans play video games. A random sample of 1100 teenagers were asked whether they play games online; 575 said they did. Is there sufficient evidence to suggest that the proportion of teens who play video games is different from the national figure? Use a 5% level of significance.

Which is the correct conclusion for this test?

Accepted Answer

Snice p-value = 5.08 x 10 ^-12 < 0.05, I reject H0. There is enough evidence to suggest a difference.

Answer

Snice p-value = 5.08 x 10 ^-12 < 0.05, I fail to reject H0. There is enough evidence to suggest a difference.

Answer

Snice p-value = 5.08 > 0.05, I fail to reject H0. There is not enough evidence to suggest a difference.

Answer

Snice p-value = 5.08 > 0.05, I reject H0. There is enough evidence to suggest a difference.

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