AP Statistics - Mixed Review

An outlier is an observation that

• is seen more frequently than the other observations in the data set

• is seen less frequently than the other observations in the data set

• is always smaller than the other observations in teh data set

• is always larger than the other observations in the data set

• is significantly different from the other observations in the data set

The Department of Health plans to test the lead level in a specific park. Because a high lead level is harmful to children, the park will be closed if the lead level exceeds the allowed limit. The department randomly selects several locations in the park, gets soil samples from those locations, and tests the saaples for their lead levels. Which of the following decisions would result from the Type I error?

• Closing the park when the lead levels are within the allowed limit

• Keeping the park open when the lead levels are in excess of the allowed limit

• Closing the park when the lead levels are in excess of the allowed limit

• Keeping the park open when the lead levels are within the allowed limit

• Closing the park because of the increased noise level in the neighborhood

The principal of a school is interested in estimating the average income per family of her students. She selects a random sample of students and collects information about their family income. A 95 percent confidence interval computed from the data for the mean income per family is ($35,095, $45,005). Which of the following provides the best interpretation of this confidence interval?

• 95 percent of the students in her school are from families whose income is between $35,095 and $45,005

• There is a 95% probability that the families of all the students in this school have an income of between $35,095 and $45,005

• If we were to take another sample of the same size and comput a 95 percent confidence interval, we would have a 95% chance of getting the interval ($35,095, $45,005)

• There is a 95% probability that the mean of another sample with the same size will fall between $35,095 and $45,005

• There is a 95% probability that the mean income per family in the school is between $35,095 and $45,005

Tags

CCSS.HSS.IC.B.4

A botanist is interested in testing H₀: μ=3.5 cm versus μ>3.5, where H_a: μ>3.5, where μ=the mean petal length of one variety of flowers. A random sample of 50 petals gives significant results at a 5 percent level of significance. Which of the following statements about the confidence interval to estimate the mean petal length is true?

• The specified mean length of 3.5cm is within a 90 percent confidence interval.

• The specified mean length of 3.5 cm is not within a 90 percent confidence interval.

• The specified mean length of 3.5 cm is below the lower limit of a 90 percent confidence interval.

• The specified mean length of 3.5 cm is below the lower limit of a 95 percent confidence interval

• Not enough information is available to answer the question.

According to the central limit theorem, the sample mean X is approximately normally distributed

• for a large sample, regardless of the distribution of random variable X

• for a large sample, provided the random variable X is normally distributed

• regardless of the sample size

• for a small sample, regardless of the distribution of random variable X

• for a small sample, provided the random variable X is normally distributed

A dentist has noticed that about two children in every seven whom he sees professionally develop cavities before they turn 10 years old. Last week he examined the teeth of five unrelated children younger than 10. Let X be the number of children who develop cavities before turning 10. Which of the following gives the probability that at least one will develop a cavity before turning 10?

• P(X=2,3,4,5,6,7)

• P(X=2 out of 7)

• P(X=1)

• 1-P(X=0)

• P(X=0,1)

A school committee member is lobbying for an increase in the gasoline tax to support the county school system. The local newspaper conducted a survey of county residents to assess their support for such an increase. What is the population of interest here?

• All school-aged children

• All county residents

• All county residents with school-aged children

• All county residents with children in the county school system

• All county school system teachers

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1

A department store at a large mall claims that over 60 percent of the mall's visitors shop at that store. Let p= the proportion of the mall's visitors who shop at the store. Which of the following pairs of hypotheses should be used to support this claim?

• H₀: p≤0.60 and H_a: p > 0.60

• H₀: p=0.60 and H_a: p ≠0.60

• H₀: p=0.60 and H_a: p < 0.60

• H₀: p>0.60 and H_a: p ≤ 0.60

• H₀: p<0.60 and H_a: p ≥ 0.60

A manufacturer of ready-bake cake mixes is interested in designing an experiment to test the effects of four different temperature levels (300, 325, 350, and 375°F), two different types of pans (glass and metal), and three different types of ovens (gas, electric, and microwave) on the texture of its cakes, in all combinations. Which of the following below is the best description of the design of the necessary experiment?

• A completely randomized design with nine treatment groups

• A completely randomized design with 24 treatment groups

• A randomized block design, blocked on temperature, with six treatment groups

• A randomized block design, blocked on type of pan, with 12 treatment groups

• A randomized block design, blocked on type of oven, with eight treatment groups

Tags

CCSS.HSS.IC.B.3

A chi-square test of independence is to be performed on a 3x4 contingency table. How many degrees of freedom does this test have?

• 6

• 8

• 10

• 11

• 12