A marketing researcher for a phone company surveys 130 people and finds that the proportion of customers who are likely to switch providers when their contract expires is 12​%. Complete parts​ a) and​ b) below. ​a) What is the standard deviation of the sampling distribution of the​ proportion? SD (ModifyingAbove p with caret )equals nothing ​(Round to four decimal places as​ needed.) ​b) If she wants to reduce the standard deviation by​ half, how large a sample would she​ need? nequals nothing ​(Type a whole​ number.)

Identify the statement below as either descriptive or inferential statistics. upper a certain website sold an average of 117 books per day last week. is the statement an example of descriptive or inferential statistics? a. it is an example of descriptive statistics because it uses a sample to make a claim about a population. b. it is an example of inferential statistics because it uses a sample to make a claim about a population. c. it is an example of inferential statistics because it summarizes the information in a sample. d. it is an example of descriptive statistics because it summarizes the information in a sample.