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Distributions
Studies & Prob
Hypothesis Tests
More Hyp Tests
Unit 11 and 12
100

Which of the following distributions are likely to be skewed to the right? I. Household prices II. Home prices III. Ages of teenage drivers

What is I and II

100
A method of data collection that involves separating samples into different strata based on covariate characteristics.
What is stratified sampling
100

A student reasons that he will or will not receive a 5 on the AP Statistics Exam, and therefore the probability of receiving a 5 is .50. Why is this incorrect reasoning?

Obviously.

JK, this is binary, not equal probability.

100
df= (r-1) (c-1)
What is the formula for degrees of freedom when conducting a chi square test for independence.
100
You roll two dice. What is the probability that the sum is 6 given that one die shows a 4?
What is 2/11
200
Which of the following are true statements? I. All symmetric histograms have single peaks II. All symmetric bell-shaped curves are normal III. All normal curves are bell-shaped and symmetric
What is III only
200
A method of sampling in which the researcher divides the population into separate groups, then a simple random sample of groups is selected from the population.
What is cluster sampling
200
According to a CBS poll taken in 1992, 15% of the public have responded to a telephone call-in poll. In a random group of five people, what is the probability that exactly two have responded to a call-in poll?
What is .138
200
A geneticist claims that four species of fruit flies should appear in the ratio 1:3:3:9. Suppose that a sample of 2000 flies contained 110,345,360, and 1185 flies of each species. Is there sufficient evidence to reject the geneticist's claim?
The data gives sufficient evidence to reject the geneticist's claim.
200

It turns out that 25 seniors at Fashionable High School took both the AP Statistics exam and the AP Spanish Language exam. The mean score on the Statistics exam for the 25 seniors was 2.4 with a standard deviation of 0.6 and the mean score on the Spanish Language exam was 2.65 with a standard deviation of 0.55. We want to combine the scores into a single score. What are the correct mean and standard deviation of the combined scores?

5.05; you cannot determine the standard deviation from this information because the students were not independent.

300

Suppose the average score on a national test is 500 with a standard deviation of 100. If each score is increased by 25% and then we subtract 100, what are the new mean and standard deviation?

What is 525 and 125

300
A general statistical term meaning a systematic favoring of certain outcomes.
What is bias
300
A pharmaceutical company claims that a medicine will produce a desired effect for a mean time of 58.4 minutes. A government researcher runs a hypothesis test of 40 patients an calculates a mean of 59.5 minutes with a standard deviation of 8.3 minutes. What is p-value?
What is 2P(t>.838)
300
Suppose H0:p=.4 and the power of the test for the alternative hypothesis p=.35 is .75. What is the probability of failing to reject H0?
What is .25
300

The 2000 Census identified the ethnic breakdown of the state of California approximately as follows: White: 46%, Latino: 32%, Asian: 11%, Black: 7%, and Other: 4%. Assuming that these are mutually exclusive categories (this is not a realistic assumption, especially in California), what is the probability that a random selected person from the state of California is of Asian or Latino descent?

What is 43%

400
If quartiles Q1=20 and Q3=30, which of the following must be true? I. The median is 25 II. The mean is between 20 and 30 III.The standard deviation is at most 10
What is none of the above
400

This is the concept where the experimental probability tends toward the true probability as you perform more trials.

What is the law of large numbers

400

A school superintendent must make a decision whether or not to cancel school because of a threatening snowstorm. This is the result of a Type I error.

What is weather remains dry, but school is needlessly canceled.

400

Which is typically more severe, Type I or Type II error?

Depends on the context.

400

You own an unusual die. Three faces are marked with the letter "X," two faces with the letter "Y," and one face with the letter "Z." What is the probability that at least one of the first two rolls is a "Y"?

What is 5/9

500

When a set of data has suspect outliers, these are the preferred measures of center and spread.

What are median and IQR?

500

This is the probability and event will occur given that another event has occurred.

What is conditional probability?

500

This is the probability of mistakenly failing to reject a false null hypothesis when a hypothesis test is being conducted at the 5% significance level.

What is β?

500

The probability of correctly rejecting the null hypothesis when the null hypothesis is false.

What is power?

500

The GPA (grade point average) of students who take the AP Statistics exam is approximately normally distributed with a mean of 3.4 with a standard deviation of 0.3. What is the probability that a student selected at random from this group has a GPA lower than 3.0?

What is 0.0918