A machine cuts plastic into sheets that are 45 feet (540 inches) long. Assume th

Question

A machine cuts plastic into sheets that are 45 feet (540 inches) long. Assume that the population of lengths is normally distributed. Complete parts (a) and (b). (a) The company wants to estimate the mean length the machine is cutting the plastic within 0.125 inch. Determine the minimum sample size required to construct a 95% confidence interval for the population mean. Assume the population standard deviation is 0.25 inch. nequals=nothing (Round up to the nearest whole number as needed.) (b) Repeat part (a) using an error tolerance of 0.0625 inch. nequals=nothing (Round up to the nearest whole number as needed.) Which error tolerance requires a larger sample size? Explain.

Explanation / Answer

a)here margin of error E =0.125

for 95% confidence interval ; z score =1.96

therefore sample size n=(z*Std deviation/E)2 =~16

b) for margin of error E = 0.0625

sample size n=(z*Std deviation/E)2 =62

for part b) havin a lower margin of error requires a larger sample size

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.