from a simple random sample. (Assume data collection quality is same for both.)
b. FALSE (Random samples are NOT BIASED, no
matter what size they are. A larger random sample has more
precise/consistent results than a small sample does, but that is not related to
bias. A biased sample is one that was collected on the basis of systematic
favoritism of a group of individuals in the population
. That does not happen
with random samples. (See 3.1 notes))
23. Which of the following is NOT in the same units as the original data?
a. Standard deviation
Y-intercept of the regression line
All of the above are in the same units as the original data.
24. The residuals from a regression line are in the same units as the Y values.
TRUE (residual = observed y – expected y from the line; both are in the same
25. It is possible to have a data set where Q1 is equal to the median.
Example: 1, 1, 1, 1, 1, 1, 1, 1.
All numbers in the 5 numbers summary equal
Example: 1, 1, 1, 1, 1, 5, 5, 5.
Q1 = 1, Median = 1
Example: 0, 2, 2, 2, 2, 2, 3, 4.
Q1 = 2, Median = 2
This occurs when all the data are the same between the value of Q1 and the Median.
The rest of the data can be anything.