Question

15 points] 6. A population has a mean of 126. If a random sample of 8 items from the population results in the following sampled values, what is the sampling error for the sample? 134 138 105 142 148 137 114 115 [10 points] 7. A company manager thinks he is overpaying for fertilizer at $175 per ton. To find out, he collects fertilizer prices per ton from five distributors. a. Construct a 90% confidence interval for the true mean, given the following collected data: [128, 140, 180, 166, 156]. b. Do you agree with the manager's thought? Why or Why not?

Answer 1

6)
FRom the gievn data

Std.dev = 15.5695 , n = 8
= 15.5695/sqrt(8)
= 5.5047

7)

From the given data

mean = 154
s = 20.5913 , n =5

t value at 90% = 2.7764

CI = mena +/- t *(s/sqrt(n))
= 154 +/- 2.7764 *(20.5913/sqrt(5))
= (128.4329 ,179.5671)

b)

N0, because confidence interval contain 175