WorksheetsAP Stats Chapters
Total questions: 15
Worksheet time: 15mins
(a) is the use of a regression line for prediction outside the interval of x values used to obtain the line.
The ___________________ measures the percent of the variability in the response variable that is accounted for by the least-squares regression line.
coefficient of determination
x2
r2
coefficient of relaxation
Which of the following definitions are true...
Points with high leverage in regression have much larger or much smaller x values than the other points in the data set.
An outlier in regression is a point that does not follow the pattern of the data and has a large residual.
An influential point in regression is any point that, if removed, substantially changes the slope, y intercept, correlation, coefficient of determination, or standard deviation of the residuals.
All of the above
What equation for the LSRL would be most reasonable for this data?
y=30.57+1.89x
y=−26.16+1.58x
y=−42.12−1.26x
y=42.56−1.39x
The equation y=−26.16 + 1.58x can be used to predict a student's heart rate after a brisk walk around the school, if their resting heart rate (before the walk) is known. Interpret the slope of the LSRL.
A student's heartrate after the walk will be 1.58 times what their resting heartrate is.
If a student's resting heartrate increases 1 bpm, their heartrate after the walk is predicted to decrease 26.16 bpm
If a student's resting heartrate increases 1 bpm, their heartrate after the walk is predicted to increase 1.58 bpm
A student's heartrate before the walk is predicted to be 26.16 bpm lower than after the walk.
What type of correlation exists between the number of people that go to the pool and the temperature outside.
positive
negative
no correlation
unknown
The scores on a statistics exam had a mean of 81 and a standard deviation of 9. One student was absent on the test day, and his score wasn't included in the calculation. If his score of 84 is added to the distribution of scores, what would happen to the mean and standard deviation?
mean will increase, standard deviation will increase
mean will increase, standard deviation will decrease
mean will increase, standard deviation will stay the same
mean will decrease, standard will decrease
If a distribution is skewed to the right with no outliers,
mean<median
mean>median
mean=median
can not determine
Which of the following statements about this distribution is not correct?
The histogram is skew right.
The median is less than the $20.
The IQR is $35.
The mean is greater then the median.
True or false: The IQR is a resistant measure of spread.
True
False
A survey was designed to study how business operations vary according to their size. Companies were classified as small,medium, or large. Questionnaires were sent to 200 randomly selected businesses of each size. Because not all questionnaires in a survey of this type are returned, researchers decided to investigate the relationship between the response rate and the size of the business. The data are given in the following two-way table:
What percent of all small companies receiving questionnaires responded?
20.8%
33.3%
50.8%
62.5%
The mean salary of all female workers is $35,000. The mean salary of all male workers is $41,000. What must be true about the mean salary of all workers?
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 must be larger than $38,000.
Rain water was collected at 30 sites and the pH level was measured. The mean and standard deviation of values of 4.60 and 1.10, respectively. When the pH meter was recalibrated back at the laboratory, it was found to be an error. The error can be corrected by adding 0.1 pH units to all the values and then multiplying the result by 1.2. The mean and standard deviation of the corrected pH measurements are
5.64, 1.44
5.40, 1.44
5.64, 1.20
5.64, 1.32
If the heights of American men follow the Normal distribution, and 99.7% have heights between 5'0'' and 7'0'', what is your estimate of the standard deviation of the height of American men?
1"
3"
4"
6"
What is the standardized score (z-score) for a student who scored 500 on the old SAT scale?
-30
-0.13
0.13
0.27
