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WorksheetsStat 269 Exam 1 Review
Total questions: 36
Worksheet time: 39mins
What are 3 Measures of Central Tendency?
A generic brand of the anti-histamine Diphenhydramine markets a capsule with a 50 milligram dose.
State the null and alternative hypothesis.
In a type 1 error.....
the null is true but we reject it
the null is false and we reject it
the null is true and we fail to reject it
the null is false but we fail to reject it
In a type II error...
we reject the null when it is false
we reject the null when it is true
accept the null when it is false
we fail to reject the null when it is true
An experiment is conducted to determine whether a new treatment helps patients with diabetes.
H0: The treatment does not work.
Ha: The treatment works.
Which of the following is a Type I Error in this situation?
the treatment does not work, but we believe that it does
the treatment does not work, and we believe it does not work
the treatment works, and we believe that it works
the treatment works, but we think that it doesn't
An experiment is conducted to determine whether a new treatment helps patients with diabetes.
H0: The treatment does not work.
Ha: The treatment works.
Which of the following is a Type II Error in this situation?
the treatment does not work, but we believe that it does
the treatment does not work, and we believe it does not work
the treatment works, and we believe that it works
the treatment works, but we think that it doesn't
An experiment is conducted to determine whether a new treatment helps patients with diabetes.
H0: The treatment does not work.
Ha: The treatment works.
Which of the following would NOT be errors in this situation? (select all that apply)
the treatment does not work, but we believe that it does
the treatment does not work, and we believe it does not work
the treatment works, and we believe that it works
the treatment works, but we think that it doesn't
A large university is curious if they should build another cafeteria. They plan to survey a sample of their students to see if there is strong evidence that the proportion interested is higher than 40%, in which case they would consider building the new cafeteria. Here are the hypotheses they'll use:
H0: p ≤ 0.40, Ha: p > 0.40
In a Type ___ error, the university will build a new cafeteria when the students don't want it.
I
II
A large university is curious if they should build another cafeteria. They plan to survey a sample of their students to see if there is strong evidence that the proportion interested is higher than 40%, in which case they would consider building the new cafeteria. Here are the hypotheses they'll use:
H0: p ≤ 0.40, Ha: p > 0.40
In a Type ___ error, the university will not build a new cafeteria when the students want it.
I
II
What can you do to lower the probability of making a Type I error? (check all that apply)
Choose a smaller alpha
Choose a larger sample
Choose a larger alpha
Choose a smaller sample
Which of the following is the FIRST step of a hypothesis test?
Check assumptions & conditions
Find your test statistic
State your conclusion
State your null & alternative hypotheses
A grocery store announces that the average wage of its employees is $12.50/hour. The claim made would be w=12.50. Is this the null or alternative hypothesis?
null
alternative
What is " a decision-making process for evaluating claims about a population"?
Population Testing
Sample Testing
Hypothesis Testing
What symbols are used to represent the probabilities of type I and II errors?
1,2
α, β
A,B
At Dominique's Donuts the number of donut holes in a bag can vary. Help Dominique find the mode.
12,10,10,10,13,12,11,13,10
13
11
12
10
What is the mode?
the number that is occurring the most
biggest - smallest
the average
the middle number
Find x of these numbers representing the number of DVDs students in an apartment each own
10, 4, 6, 8, 4
6
6 DVDs
6 DVDs2
Find the Q0.5 of these numbers:
4,2,7,4,3
2
7
5
4
To find the mean of a set of numbers, add up all the items and divide by
2
the maximum
N
the minimum
In order to find percentiles, the data must be sorted from least to greatest first.
true
false
What is the range?
average
R
biggest - smallest
# occurring the most
The number of pages that Carolyn wrote in her journal each day from Monday to Friday is shown below:
9, 8, 12, 6, 10
Find the variance.
2.24 pages per day
2.24 (pages per day)2
5 pages per day
5 (pages per day)2
The number of pages that Carolyn wrote in her journal each day from Monday to Friday is shown below:
9, 8, 12, 6, 10
Find the standard deviation
2.24 pages per day
2.24 (pages per day)2
5 pages per day
5 (pages per day)2
The probability of a type 1 error is
alpha
beta
sigma
1-beta
One ESP (extra sensory perception) test asks the subject to view the backs of cards and identify whether a circle, square, star , or cross is on the front of each card. If p is the proportion of correct answers, this may be viewed as a hypothesis test with H0: p = 0.25 and Ha: p > 0.25. The subject is recognized to have ESP when the null hypothesis is rejected. What would a Type II error result in?
Correctly recognizing someone has ESP
Mistakenly thinking someone has ESP
Not recognizing that someone really has ESP
Correctly realizing that someone doesn't have ESP
Failing to understand the nature of ESP
A school superintendent must make a decision whether or not to cancel school because of a threatening snow storm. What would the results be of Type I and Type II errors for the null hypothesis: The weather will remain dry?
Type I error: don't cancel school but the snow storm hits.
Type II error: the weather remains dry, but school is needlessly canceled.
Type I error: the weather remains dry, but school is needlessly canceled.
Type II error: don't cancel school, but the snow storm hits.
Type I error: cancel school, and the storm hits.
Type II error: don't cancel school , and the weather remains dry.
Type I error: don't cancel school, and the snow storm hits.
Type II error: don't cancel school , and the weather remains dry.
Type I error: don't cancel school , and the weather remains dry.
Type II error: cancel school, and the storm hits.
A researcher plans to conduct a test of hypotheses at the α = 0.01 significance level. She designs her study to have a power of 0.90 at a particular alternative value of the parameter of interest. The probability that the researcher will commit a Type I error is
0.01
0.10
0.90
0.99
When leaving for school, you make a judgement on these hypotheses. Ho: The weather will remain dry. Ha: It will rain. What are the results of the Type I and Type II errors?
Type I: Needlessly carry around an umbrella all day. Type II: Get drenched
Type I: Get drenched. Type II: Needlessly carry around an umbrella all day
Type I: Carry umbrella & it rains. Type II: Carry no umbrella & it doesn't rain
Type I: Get drenched. Type II: Carry umbrella & it rains
An environmental scientist wants to test the null hypothesis that an antipollution device for cars is not effective. Under which of the following conditions would a Type 1 error be committed?
The scientist concludes that the antipollution device is effective when it actually is not
The scientist concludes that the antipollution device is not effective when it actually is.
The scientist concludes that the antipollution device is not effective when it actually is not.
A type 1 error cannot be committed in this situation.
Because of the expense of running a campaign, a potential candidate will only run if there is more than 40% initial support for him. To test this they take a SRS of 200 voters and ask if they would vote for him. They run a significance test with H0: p = 0.40 vs. Ha: p > 0.40. Which of the following describes a consequence of Type II error in this setting?
Thinking that there is enough support, but the candidate still decides not to run for office.
Thinking that there is not enough support, but the candidate still decides to run for office.
Thinking that there is not enough support, so the candidate decides not to run for office. The candidate saves money, but might have won because the initial support is more than 40%
Thinking that there is enough support, so the candidate decides to run for office. This is a waste of money because the initial support is not more than 40%.
A lightbulb company claims that their lightbulbs last 1000 hours. To test this claim, a consumer selects a random sample of 20 lightbulbs manufactured by the company. The consumer turned on the lightbulbs and recorded the time it took until the lightbulbs burned out. A significance test is performed using the following hypotheses at the 5% significance level: H_0:\ \mu\ =1000\ vs.\ H_a:\ \mu\ <1000
H0
: μ =1000 vs. Ha
: μ <1000
where \mu
μ
=the mean time until burn out for all lightbulbs from this company. Which of the following describes a Type I error in this setting?
The consumer does not find convincing evidence that the lightbulbs last, on average, 1000 hours, when it fact the P-value of the test was not small enough to reject the null hypothesis.
The consumer does not find convincing evidence that the lightbulbs last, on average, 1000 hours, when it fact the P-value of the test was small enough to reject the null hypothesis.
The consumer finds convincing evidence that the lightbulbs last, on average, 1000 hours, when it fact the lightbulbs last less than 1000 hours, on average.
The consumer advocate finds convincing evidence that the lightbulbs last, on average, less than 1000 hours, when it fact the lightbulbs last 1000 hours, on average.
What is the range?
2 4 4 6 7 8
6
2-8
3
4
What is the first quartile?
2 4 4 6 7 8
3
4
5
6
What is the third quartile?
4
5
6
7
What is the IQR?
2 4 4 6 7 8
3
4
5
6
What is the range?
10
12
15
2-12
