Answer Happy

Suppose 15% of smartphones sold at a retail outlet are purchased with warranty. A random sample of 37 smartphones is selected. Assuming independence, use the binomial formula or software (recommended) to answer the following questions. 1. What is the probability that, of the 37 smartphones selected: (Report probabilities accurate to at least 4 decimal places.) 4 a) exactly 5 are purchased with warranty? b) exactly 31 are not purchased with warranty? c) none of them are purchased with warranty?

d) at most 10 are purchased with warranty? e) at least 8 are purchased with warranty? f) more than half are purchased with warranty? g) at least 8 but no more than 12 are purchased with warranty? h) less than 4 or more than 11 are purchased with warranty?

2. Calculate the mean and standard deviation of smartphones that are purchased with warranty. Round to 2 decimal places. Mean = Standard Deviation = 3. If you expect to find exactly 27 smartphones that are purchased with warranty, how large a sample should you select? Report the minimum sample size required as an integer.