AP Stats Chapter 1&4 Test Review

You record the age, marital status and earned income of 1463 women. The number and type of variables you have recorded is

• 3 quantitative, 0 categorical

• 2 quantitative, 1 categorical

• 1 quantitative, 2 categorical

• 0 quantitative, 3 categorical

The percentage of actresses who were younger than 30 when they won "best actress" is closest to

• 7%

• 22%

• 29%

• 50%

Which statement about this distribution is NOT correct?

• The histogram is right-skewed

• The median age is less than 40 years

• The mean is greater than the median

• The IQR is approximately 60 years

The mean salary for all employees at store A is $35,000. The mean salary for all employees at store B is $41,000. What must be true for the mean salary of all employees?

• It must be $38,000

• It must be larger than the median salary

• It could be any number between $35,000 and $41,000

• It cannot be larger than $40,000

The dotplots show the average number of minutes two groups of students spent exercising. Which statement is not true?

• The median for seniors is the same as the median for freshmen

• The standard deviation is larger for seniors than for freshmen.

• The IQR for freshmen is 30

• The IQR for seniors is 30

Which statement is true about the amount of money students in this survey spent on homecoming?

• A majority of students spent between $40 and $80

• The student who spent $100 is an outlier in this group.

• The mean amount spent for homecoming is $40.

• The distribution is skewed right.

A data set has the following 5-number summary:

Min = 3; Q₁ = 18; Med = 24; Q₃ = 30; Max = 50

Which statement is true?

• There are no outliers

• 3 is an outlier but 50 is not.

• 50 is an outlier, but 3 is not.

• Both 3 and 50 are outliers

The distribution of scores on a test are fairly symmetric and unimodal with a peak at 80. One student who was absent then takes the test and scores 25 on the test. Which summary statistic would be least affected by the addition of this new data point?

• Standard deviation

• Mean

• IQR

• Range

A new headache remedy was given to a group of 25 subjects who had headaches. Four hours after taking the new remedy, 20 of the subjects reported that their headaches had disappeared. From this information you conclude

• that the remedy is effective for the treatment of headaches.

• nothing, because the sample size is too small.

• nothing, because there is no control group for comparison.

• that the new treatment is better than aspirin.

• that the remedy is not effective for the treatment of headaches.

A maple sugar manufacturer wants to estimate the average trunk diameter of Sugar Maple trees in a large forest. There are too many trees to list them all and take a SRS, so he divides the forest into several hundred 10 meter by 10 meter plots, selects 25 plots at random, and measures the diameter of every Sugar Maple in each one. This is an example of a

• multistage sample.

• stratified sample.

• simple random sample.

• cluster sample.

• convenience sample.