Stats homework please help

Question

1. The number of movies that four people in a family have seen in the past month is 4,2,8, and 0. Using samples of size 3 find the mean of the sampling distribution.

(a) 3.5 (b) 4.7 (c) 14 (d) 2.4

1. The mean price of photo printers on a website is $235 with a standard deviation of $62. Random samples of 30 are drawn from the population. Find the probability that the mean price of a photo printer is more than $215.

Answer 1

The sample means average the population mean: (4+2+8+0)/4 = 14/4 = 3.5

a)

1. z = (x - mu)/(sigma/sqrt(n)) = (215-235)/(62/sqrt(30)) = -1.76684695969408

P(x >= 215) = P(z >= -1.76684695969408) or P(z <= 1.76684695969408) = 0.961373069091631

Alternatively, you could use =1 - NORM.DIST(215,235,62/SQRT(30),1)