1. True or False. Justify for full credit.
(a) The volume of milk in a jug of milk is 128 oz. The value 128 is from a discrete data set.
(b) If the variance from a data set is zero, then all the observations in this data set must be zero.
(c) P(A ANDA ) 0, whereA is the complement of A. c c
(d) The mean and median for a normal distribution are always the same.
(e) In a hypothesis testing, if the p-value is less than the significance level α, we do not have sufficient evidence to reject the
null hypothesis.
Refer to the following frequency distribution for Questions 2, 3, 4, and 5. Show all work. Just the answer, without supporting
work, will receive no credit.
A random sample of 25 customers was chosen in UMUC MiniMart between 3:00 and 4:00 PM on a Friday afternoon. The
frequency distribution below shows the distribution for checkout time (in minutes).
Checkout Time (in minutes) Frequency Relative Frequency 1.0 - 1.9 6 2.0 - 2.9 8 3.0 - 3.9 4.0 - 5.9 5 Total 25
2. Complete the frequency table with frequency and relative frequency.
3. What percentage of the checkout times was less than 3 minutes?
4. In what class interval must the median lie? Explain your answer.
5. Assume that the largest observation in this dataset is 5.8. Suppose this observation were incorrectly recorded as 8.5 instead of 5.8.
Will the mean increase, decrease, or remain the same? Will the median increase, decrease or remain the same? Why?