Question

(1 point) In 2012, the percentage of cell phone owners who used their cell phone to send or receive text messages was 80%. A polling firm contacted a simple random sample of 1400 people chosen from the population of cell phone owners. If p is the proportion of cell phone owners who used their phone to text, then what was the the probability that p^ was between 0.79 and 0.81?

Answer 1

Answer:-

Given That:-

In 2012, the percentage of cell phone owners who used their cell phone to send or receive text messages was 80%. A polling firm contacted a simple random sample of 1400 people chosen from the population of cell phone owners. If p is the proportion of cell phone owners who used their phone to text, then

what was the the probability that p^ was between 0.79 and 0.81?

n= 1400 ,p = 0.80

Mean of the sample distribution is,

The standard error of the sampling distribution of sampling proportion is,

The probability is,

(Using the excel function, (NORMSDIST(z)))