Question

A guitar supply company must maintain strict oversight on the number of picks they package for sale to customers. Their current advertisement specifies between 900 and 1000 picks in every bag. An SRS of 16 1-pound bags of picks were collected as part of a Six-Sigma Quality Improvement effort within the company. The number of picks in each bag are shown as follows. Use α=0.0223α=0.0223 for all calculations below.

987,947,988,945,942,912,951,918,952,923,888,939,909,920,999,955987,947,988,945,942,912,951,918,952,923,888,939,909,920,999,955

Do the data suggest that the standard deviation in number of picks per 1-pound bag differs from 24.7?

Choose the correct statistical hypotheses.
A. H0:S=24.7HA:S≠24.7H0:S=24.7HA:S≠24.7
B. H0:S=24.7HA:S>24.7H0:S=24.7HA:S>24.7
C. H0:σ=24.7HA:σ<24.7H0:σ=24.7HA:σ<24.7
D. H0:σ=24.7HA:σ>24.7H0:σ=24.7HA:σ>24.7
E. H0:σ=24.7HA:σ≠24.7H0:σ=24.7HA:σ≠24.7


(b) Construct a 97.77% confidence interval estimate of the standard deviation of number of picks per 1-pound bag. Give answers to the nearest tenth.

(c) What assumption need to be satisfied for the inferences made in (b) to be valid? Use appropriate graph to check this assumption. Report your p-value. Three digits after decimal
P=

Do the data follow an approximately Normal distribution?

A. Yes
B. No


(d) Do the data suggest that the standard deviation in number of picks per 1-pound bag differs from 24.7?

A. Yes
B. No

Answer 1