The production department of the newspaper wants to ensure that the mean blackness of the print for all newspapers is at least 0.97 on a standard scale in which the target value is 1.0. A random sample of 50 newspapers was selected, and the blackness of on spot of each of the 50 newspapers measured. Calculate the sample statistics and determine whether there is evidence that the population mean blackness is less than 0.97.
The marketing department team was charged with improving the telemarketing process in order to increase the number of home-delivery subscriptions sold. It is known that the longer a caller speaks to a respondent, the greater the chance that the caller will sell a home-delivery subscription. Therefore, the team decided to find ways to increase the length of the call. The team investigated the impact that the time of a call might have on the length. The team selected a sample of 30 female callers and randomly assigned 15 of to the “early” time period (5-7pm) and 15 to the “later” (7-9pm) time period. The callers knew that the team was observing their efforts that evening but didn’t know which particular calls were monitored. Measurements were taken on the length of call (defined as the difference, in seconds, between the time the person answers the phone and the time she hangs up). A. Analyze the data and compare the two independent groups of callers. B. Suppose that instead of the research design described, there were only 15 callers sampled and each caller was to be monitored twice in the evening – once in the early time period and once in the later time period. Thus, each of the pairs of values represents a particular caller’s two measurements. Re-analyzed the data. How does it compare to part A.
In studying the home delivery solicitation process, the marketing department team determined that the so-called “later” calls made between 7pm and 9pm were significantly more conducive to lengthier calls than those made earlier in the evening (between 5-7pm). The team sought to investigate the effect of the type of presentation on the length of the call. A group of 24 female callers was randomly assigned, 8 each, to one of three presentation plans – structured, semi-structured, and unstructured – and trained to make the telephone presentation. All calls were made between 7-9pm and the callers were to provide an introductory greeting that was personal but informal (“Hi, this is Leigh Richardson from the XYZ Times. May I speak to John Smith?”). The callers knew that the team was observing their efforts that evening but didn’t know which particular calls were monitored. Measurements were taken on the length of call (defined as the difference, in seconds, between the time the person answers the phone and the time he or she hangs up). Analyze the data and compare the three independent groups of callers.
