WorksheetsFinal Exam Practice Test
Total questions: 45
Worksheet time: 11hrs 5mins
The probability that it will rain tomorrow is 0.30. What is the probability that it will rain OR not rain? What do we call these kinds of events?
1: complements
0: mutually exclusive
0.50: equally likely
1: independent
The scatterplot below shows the hat size and IQ of some adults. Is the correlation coefficient:
Negative
Positive
Near 100
Near 0
When a confidence interval for the difference of two population means contains 0, what can be concluded?
The population means are significant
An error was made in calculation
The population means may be the same
The results of the confidence interval are inconclusive
As a rule of thumb, when considering whether or not to apply the Central Limit Theorem to a sample drawn from a population that is not normal, what sample size is considered "large"?
10 or more
100 or more
50 or more
25 or more
In the NHL, the correlation between "Goals scored per game" and "Minutes on the ice" for a team of players is found to be 0.8178. Choose the statement that is true about the coefficient of determination.
The coefficient of determination states that about 66.88% of the variation in goals scored per game is explained by minutes on the ice.
When given as a percent, the coefficient of determination is always between 0 and 100%
The coefficient of determination, r squared r^2, is equal to approximately 0.6688.
All of these are true statements.
Only B and C are true statements
State whether the following study involves two independent or dependent samples.
The productivity of manufacturing plant workers is compared before and after the installation of air conditioning.
Dependent
Independent
According to the ancient Roman architect Vitruvius, a person's armspan (the distance from fingertip to fingertip with the arms stretched wide) is approximately equal to his or her height. For example, people 5 feet tall tend to have an armspan of 5 feet. Explain, then, why the distribution of armspans for a class containing roughly equal numbers of men and women might be bimodal.
Men and women tend to have different heights and therefore different armspans.
The class could meet at different times on different days
Some students will have an armspan less than their height, and some students will have an armspan greater than their height.
There is no reason why the distribution might be bimodal.
The mean finish time of all participants in a recent large duathlon was 1.67 hours with a standard deviation of 0.25 hours. Suppose a random sample of 30 participants in the 40-44 age group was taken and the mean finishing time was found to be 1.62 hours with a standard deviation of 0.40 hours. In this example, the numerical values of 1.62 hours and 0.40 hours are Modifying with underline.
unbiased estimators
statistics
estimates
parameters
Which measure of center should be compared: the means or the medians? Why?
Both data sets are right-skewed and have outliers; so the medians and IQRs should be compared
The distributions should be compared using the means and standard deviations because these are both symmetric distributions with no outliers.
It is appropriate to use either the medians or the means as measures of center.
Both data sets are right-skewed and have outliers; so the means and standard deviations should be compared.
A researcher wants to know if mood is affected by music. She conducts a test on a sample of 4 randomly selected adults and measures mood rating before and after being exposed to classic rock music. Test the hypothesis that mood rating decreased after being exposed to classic rock music using the accompanying data.
H0:UBefore= UAfter
Ha: UBefore > UAfter
H0:UBefore- UAfter =0.275
Ha: UBefore - UAfter< 0.275
H0: UBefore= UAfter
Ha: UBefore < UAfter
H0:UBefore < UAfter
Ha: UBefore > UAfter
Find the probability that a male college student from the group chose "housework" as their most likely activity on Saturday mornings
0.145
0.302
0.156
0.845
The mean finishing time of ALL participants in a recent large duathlon was 1.67 hours with a population standard deviation of 0.30 hours. Suppose a random sample of 30 participants was taken.
What value should we expect for the mean finishing time of this sample of 30 randomly selected participants? Why?
The expected mean finishing time is about 1.42 hours, because the sampling distribution of the mean is right-skewed.
The expected mean finishing time is about 1.67 hours, because the sample mean is an unbiased estimator of the population mean.
The expected mean finishing time is about 1.92 hours, because the sampling distribution is left-skewed.
The expected mean finishing time is about 1.67 hours, because the sample mean is always the same as the population mean.
The mean finishing time of ALL participants in a recent large duathlon was 1.67 hours with a population standard deviation of 0.30 hours. Suppose a random sample of 30 participants was taken.
What is the standard error for a sample mean taken from this population?
0.30 hours
0.055 hours
0.01 hours
0.056 hours
0.030 hours
The mean age of lead actors from the top ten grossing movies of 2007 was 36.4 years with a standard deviation of 9.87 years. Assume the distribution of the actors ages is approximately unimodal and symmetric.
Between what two values would you expect to find about 68% of the lead actors ages?
16.66 and 56.14 years
26.53 and 46.27 years
6.87 and 66.01 years
None of these
Exam 1 scores have a mean of 510 and a standard deviation of 110, while exam 2 scores have a mean of 23 and a standard deviation of 5. Assuming both types of scores have distributions that are unimodal and symmetric, which is more unusual: an exam 1 score of 790 or an exam 2 score of 29?
They are the same
The exam 1 score is more unusual
The exam 2 score is more unusual
It cannot be determined which exam score is more unusual
Suppose you just received a shipment of ten televisions. Four of the televisions are defective. If two televisions are randomly selected, compute the probability that both televisions work.
4/25
9/25
3/10
1/3
Suppose you just received a shipment of ten televisions. Four of the televisions are defective. If two televisions are randomly selected, What is the probability at least one of the two televisions does not work?
2/3
12/25
21/25
8/10
The two-way table below shows the survey results when sixty adults were asked whether they had made a clothing purchase in the last thirty days. What percentage of the sample had not made a clothing purchase in the past thirty days?
50%
35%
33%
65%
Does the graph show an increasing or decreasing trend Explain what that means in the context of these data.
The graph shows a increasing trend. School districts with higher
percentages of students taking the standardized test tend to have higher mean quantitative scores.
The graph shows a decreasing trend. School districts with lower
percentages of students taking the standardized test tend to have lower mean quantitative scores.
The graph shows a decreasing trend. School districts with higher
percentages of students taking the standardized test tend to have lower mean quantitative scores.
The graph shows a decreasing trend. School districts with lower
percentages of students taking the standardized test tend to have higher mean quantitative scores.
Is it appropriate to find the correlation for these data? Why or Why not?
Yes, because the trend is linear
No, because the trend is nonlinear
Yes, because the trend is nonlinear
No, because the trend is linear
Describe the sampling distribution of
p-HAT. Round to three decimals. N=12,000, n=550, p=0.3
Exactly normal; Up=0.3, Óp=0.020
Approximately normal: Up=0.3, Óp=0.020
Approximately normal: Up=0.3, Óp=0.132
Binomial: Up=165, Óp=10.747
Given the table above. What would the calculation for the Chi-Square X2 look like?
The following linear regression model can be used to predict ticket sales at a popular water park.
Predicted Ticket sales per hour= −631.25+11.25(current temp°F).
What is the predicted number of tickets sold if the current temperature is 86 degrees?
About 252 tickets
About 301 tickets
About 276 tickets
About 336 tickets
The following linear regression model can be used to predict ticket sales at a popular water park.
Predicted Ticket sales per hour= −631.25+11.25(current temp°F).
State the meaning of the slope.
The slope says that a one degree increase in temperature is associated with an average increase in ticket sales of 11.25 tickets.
The slope says that high temperatures are causing more people to buy tickets to the water park
The slope says that if ticket sales are decreasing there must have been a drop in temperature
None of these
The following linear regression model can be used to predict ticket sales at a popular water park.
Predicted Ticket sales per hour= −631.25+11.25(current temp°F).
Does the intercept have a reasonable interpretation?
There is not enough information available to solve this problem
Yes it is reasonable for people to go to a water park when it is 0 degrees, so managers might want to know how many tickets they would sell
No at a temperature of 0 degrees, ticket sales would be -631.25 and it is not reasonable (or possible) to have negative ticket sales
A researcher collects a sample of 15 measurements from a population and wishes to find a 90% confidence interval for the population mean. What value should he use for t*?
1.96
1.28
1.761
2.56
A researcher collects a sample of 15 measurements from a population and wishes to find a 90% confidence interval for the population mean. If he instead decides to use a 95% confidence interval, will the interval be wider, be narrower, or stay the same? Why?
The interval will be wider because t* is bigger, which makes the margin of error bigger.
The interval will be narrower because t* is smaller, which makes the margin of error smaller
The interval will be wider because t* is smaller, which makes the margin of error bigger
The interval will be narrower because t* is bigger, which makes the margin of error smaller
The weights at birth of five randomly chosen baby Orca whales were 425, 454, 380, 405, and 426 pounds. Assume the distribution of weights is normally distributed. Find a 95% confidence interval for the mean weight of all baby Orca whales. Use technology for your calculations. Give the confidence interval in the form estimate ± margin of error.
384.0 ± 68.0 pounds
418.0 ± 34.5 pounds
418.0 ± 34.1 pounds
410 ± 38.7 pounds
In a 2003 study on dreaming, an investigator attempted to replicate an experiment by Middleton in 1942. The 2003 researchers reported with 95% confidence that 83.9% dream in color with a margin of error of 6.81%.
In the study from 1942, 29.24% of people reported dreaming in color. Is 29.24% plausible as the 2003 population percentage?
The interval does not capture 29.24%. This shows that the results were quite different from the results in 1942.
The interval does capture 29.24%. This shows that the results were quite different from the results in 1942.
The interval does capture 29.24%. This shows that the results were quite similar from the results in 1942.
The interval does not capture 29.24%. This shows that the results were quite similar from the results in 1942.
A janitor at a large office building believes that his supply of light bulbs has too many defective bulbs. The janitor's null hypothesis is that the supply of light bulbs has a defect rate of p=0.09. Suppose he does a hypothesis test with a significance level of 0.05. Symbolically, the null and alternative hypothesis are as follows: H0: p=0.09 and Ha: p>0.09. Choose the statement that best describes the significance level in the context of the hypothesis test
The significance level of 0.05 is the defect rate we believe is the true defect rate
The significance level of 0.05 is the probability of concluding that the defect rate is equal to 0.09 when in fact it is greater than 0.09
The significance level of 0.05 is the probability of concluding that the defect rate is higher than 0.09 when in fact the defect rate is equal to 0.09
The significance level of 0.05 is the test statistic that we will use to compare the observed outcome to the null hypothesis
Suppose the janitor tests a sample of his light bulbs and uses the sample proportion of defective bulbs to compute the z-statistic for a one-proportion z-test. Symbolically, the null and alternative hypothesis are as follows: H0: p=0.09 and Ha: p>0.09. He obtains z = 1.21. Find the p-value for the test.
0.113
0.226
0.887
0.774
The boxplot shows the temperature for six cities. Which cities tend to be the warmest?
B and E
A and F
D and E
D and F
Which city has the most variation in temperature?
F
B
C
D
E
Which cities have the least variation in temperature?
D and E
A and D
A and E
B and F
Eric wants to go skiing tomorrow but only if there are 4 inches or more of new snow. According to the weather report, any amount of new snow between 3 inches and 8 inches is equally likely. What will the shaded probability density curve for tomorrow's new snow depth look like?
The mean quantitative score on a standardized test for female students was 500. The population standard deviation was 100. What percentage of the female students score above 675? Use the z- table or statcrunch
97.995%
95.99%
2.01%
4.01%
According to the Regional Bar Association, approximately 63% of the people who take the bar exam to practice law pass the exam.
Find the approximate probability that at least 64% of 300 randomly sampled people taking the bar exam will pass. Use statcrunch: P(p-hat ≥ 0.64)=
0.028
0.641
0.033
0.359
A pair of surfers collected data on the self-reported numbers of days surfed in a month for 30 longboard surfers and 30 shortboard surfers. If given data where in statcrunch do I got to find the medians, IQR, mean etc..
Summary Stats --> Columns
T-stats --> two samples --> With data
Regression --> Simple linear
Graphs --> Boxplot
If given a table that shows a list of the weights and prices of some turkeys at different supermarkets. How would you use statcrunch to find the scatterplot, correlation and regression equation?
Regression --> Simple linear
T-stats --> two samples --> with data
Proportion Stats --> One sample --> with summary
Summary Stats --> Columns
Suppose a city official conducts a hypothesis test to test the claim that the majority of voters support a proposed tax to build sidewalks. The calculated test statistic is approximately 1.40 with an associated p-value of approximately 0.081 and use a significance level of 0.05.
If the null hypothesis is true, then the probability of getting a test statistic that is as extreme than the calculated test statistic of 1.40 is 0.081. This result is not surprising and could easily happen by chance
The p-value should be considered extreme. Therefore, the hypothesis test proves that the null hypothesis is true.
If the null hypothesis is true, then the probability of getting a test statistic that is as extreme than the calculated test statistic of 1.40 is 0.081. This result is surprising and could not easily happen by chance
The p-value should be considered extreme. Therefore, the hypothesis test proves that the null hypothesis is false
Assume a standard Normal distribution. Draw a well-labeled Normal curve and find the z-score that gives a left area of 0.6638. Use statcrunch or table. What is z?
0
-0.42
0.42
0.66
-0.66
A researcher believes that children who attend elementary school in a rural setting have lower obesity rates then children who attend elementary school in an urban setting. They records the proportion of children in each sample who are clinically obese. 0.05 sign.level.
Z= 1.95, p=0.026, There is sufficient evidence to prove that the population proportions are the same
Z= -1.95, p=0.026, There is sufficient evidence to reject the null hypothesis
Z= -1.95, p=0.026, There is not sufficient evidence to reject the null hypothesis
Z= -1.85, p=0.032, There is sufficient evidence to accept the null hypothesis
A researcher measures mood rating before and after being exposed to classic rock music. Test the hypothesis that mood rating decreased after being exposed to classic rock music. If in part A you answered that the hypothesis test statements are:
H0: µBefore = µAfter Ha: µBefore > µAfter.
How would use find the p-value using statcrunch?
Z-stats --> two samples --> with data
T-stats --> two samples --> with data
T-stats --> paired --> with data
Proportion stats--> two samples--> with summary
A group of researchers counted ones, twos, threes, fours, and fives from a few lines of a random number table, and they should expect to get equal numbers of each. test the hypothesis that the random number table does not generate equal proportions of ones, twos, threes, fours, and fives, using a significance level of 0.05.
Ho: The random number table does not generate each number 20% of the time.
Ha: The random number table generates each number 20% of the time
Ho: The random number table does not generate each number 10% of the time.
Ha: The random number table generates each number 10% of the time
Ho: The random number generate each number 20% of the time.
Ha: The random number table does not generates each number 20% of the time
Ho: The random number generate each number 20% of the time.
Ha: The random number table does not generates each number 20% of the time
There are tables on the final that have data in them or includes the summary. Or the questions overview includes data points. What do I do ONLY IF there is no button to put the information into statcrunch or copy and paste?
Take the L
Manually write in the data point in a column or put in the summary information
Cry
Ask someone if you are unsure
