from a simple random sample. (Assume data collection quality is same for both.)
a.
TRUE
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
b. Q1
c.
Y-intercept of the regression line
d.
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.
a.
TRUE (residual = observed y – expected y from the line; both are in the same
units.)
25. It is possible to have a data set where Q1 is equal to the median.
a.
TRUE
b. FALSE
Example: 1, 1, 1, 1, 1, 1, 1, 1.
All numbers in the 5 numbers summary equal
one.
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.
4