Which of the following best describes measures of center?

Which of the following best describes measures of center?
 a. They are numbers around which observations tend to cluster and that describe the location of what in some sense might be called the center of a data set.
  b. They are numbers that indicate the spread or scatter of observations and show the extent to which individual values in a data set differ from one another and, hence, differ from their central location.
  c. They are numbers that indicate the degree of asymmetry in a frequency distribution.
  d. None of these.
  e. All of these.

Q. 2

A Type B correct decision occurs when the null hypothesis is true, and the decision is in opposition to the null hypothesis.
  Indicate whether the statement is true or false

Q. 3

Data about qualitative variables can be summarized by:
 a. measures of center
  b. measures of variability
  c. proportions
  d. measures of relative standing
  e. all of these

Q. 4

A Type I error is committed when a true null hypothesis is rejected - that is, when the null hypothesis is true but we decide against it.
  Indicate whether the statement is true or false

Q. 5

In a histogram, the proportion of the total area which must be to the left of the median is:
 a. exactly 0.50
  b. less than 0.50 if the distribution is skewed to the left
  c. more than 0.50 if the distribution is skewed to the right
  d. between 0.25 and 0.75 if the distribution is symmetric
  e. all of these

Q. 6

A Type A correct decision occurs when the null hypothesis is false, and we decide in its favor.
  Indicate whether the statement is true or false

Q. 7

Which of the following statements about the mean is not always correct?
 a. The sum of the deviations from the mean is zero.
  b. Half of the observations are on either side of the mean.
  c. The mean is a measure of the middle (center) of a distribution.
  d. The value of the mean times the number of observations equals the sum of all of the observations.
  e. The sum of the deviations from the mean is zero and half of the observations are on either side of the mean.

Q. 8

Hypothesis is a statement that something is true.
  Indicate whether the statement is true or false