in a survey of mobile phone owners 53% of iPhone users and 42% of android phone users indicated that they upgraded their phones at least every two years. the reported percentages were based on large samples that were thought to be representative of the population of iPhone users and the population of android phone users. the sample sizes were 8234 for the iPhone sample and 6072 for the android phone users. suppose you want to decide if there is evidence that the proportion of iPhone owners who upgrade their phones at least every two years is greater than this proportion for android phone users. let P1 be the actual proportion of i phone owners who upgrade their phones at least every two years, and P2 be the actual proportion of android owners who upgrade their phones at least every two years.

b.) are the two samples large enough for the large sample test for a difference in population proportions to be appropriate? let P1=0.53 and P2=0.42, n2=6072. since n1p1=______, n1(1-p1) =______, n2p2=_____, _____ all at least 10, the sample size _____ large enough to use the large sample confidence interval.

c.) based on the following Minitab output what is the value of the test statistic and what is the value of the associated Pvalue? round your test statistic to two decimal places and your P value to three decimal places.

test and CI for two proportions

sample X N Sample p

1. 4364 8234 0.529998

2. 2550 6072 0.419960