Fowle Marketing Research, Inc., bases charges to a client on the assumption that telephone surveys can be completed in a mean ti
me of 15 minutes or less. If a longer mean survey time is necessary, a premium rate is charged. Suppose a sample of 35 surveys produces the data in the Microsoft Excel Online file below. Use a known σ = 3.6 minutes. Is the premium rate justified? 20.3
a) Null hypothesis: the mean time of telephone surveys is less than or equal to 15 minutes. Alternative hypothesis: the mean exceeds 15 minutes. b) The computed test statistic is 2.15. c) The p-value found is 0.0158. d) NO, there is significant evidence to support that the mean survey time is fewer than 15 minutes, thus the premium rate is not warranted. Explanation: Data from Microsoft Excel includes: 17, 11, 12, 23, 20, 23, 15, 16, 23, 22, 18, 23, 25, 14, 12, 12, 20, 18, 12, 19, 11, 20, 21, 11, 18, 14, 13, 13, 19, 16, 10, 22, 18, 23. a) The null and alternative hypotheses stem from the assumption that Fowle Marketing Research Inc. bases its charges on the premise that the mean time of a telephone survey is 15 minutes or less.
