AP Statistics: Midterm review

School administrators collect data on students attending the school. Which of the following variables is quantitative?

• Class

• Whether the student is in AP classes

• Whether the student has taken the SAT

• GPA

• None of these

A professor has kept records on grades that students have earned in his class. If he wants to examine the % of students earning the grades A, B, C, D, and F during the most recent term, which kind of plot would he make?

• boxplot

• timeplot

• pie chart

• histogram

• dotplot

2 sections of a class took the same quiz. Section A has 15 students who had a mean score of 80, and Section B had 20 students with a mean score of 90. Overall, what was the approximate mean score for all of the students on the quiz?

• 85.7

• 84.3

• 85

• None of these

Suppose that a normal model described student scores in a history class. Parker has a standardized score (z-score) of +2.5. This means that Parker:

• is 2.5 points above average for the class

• has a standard deviation of 2.5

• has a score that is 2.5 times the average for the class

• is 2.5 standard deviations above average for the class

• none of these

Your Stats teacher tells you that your test score was in the 3rd quartile for the class. Which is true?

I) You got 75% on the test

II) You can't really tell what this means without knowing the standard deviation

III) You can't really tell what this means unless the class distribution is nearly normal

• I only

• III only

• II and III

• II only

• None of these

The advantage of making a stem and leaf display instead of a dotplot is that a stem and leaf display:

• satisfies the area principle

• preserves the individual data values

• shows the shape of the distribution better than a dotplot

• is for quantitative data, while a dotplot is for categorical data

• none of these

The 5 number summary of credit hours for 24 students in a statistics class is:
Min:13
Q1:15
Median: 16.5
Q3: 18
Max: 22
From the info we know:

• there is at least one low outlier in the data

• there is at least one high outlier in the data

• there are both low and high outliers in the data

• there are no outliers in the data

• none of these

Which of the followinf data summaries are changed by adding a constant to each data value?

I) the mean

II) the median

III) the standard deviation

• I and III

• I only

• III only

• I, II, and III

• I and II

If we want to discuss gaps and clusters in a data set, which of the following should NOT be chosen to display the data set?

• dotplot

• boxplot

• stem and leaf plot

• histogram

• any of these would work

All BUT one of these statements contain a mistake. Which one is true?

• The correlation between a football players weight and the position he plays is .54

• The correlation between a car's length and its fuel efficiency is .71 mpg

• There is a correlation of .63 between gender and political party

• There is a high correlation of 1.09 between height of a corn stalk and its age in weeks

• The correlation between the amount of fertilizer used and the yield of beans is .42