Question

A CI is desired for the true average stray-load loss μ (watts) for a certain type of induction motor when the line current is held at 10 amps for a speed of 1500 rpm. Assume that stray-load loss is normally distributed with σ = 2.9. (Round your answers to two decimal places.)

(a) Compute a 95% CI for μ when n = 25 and x = 51.2

( , ) watts

(b) Compute a 95% CI for μ when n = 100 and x = 51.2.

( , ) watts

(c) Compute a 99% CI for μ when n = 100 and x = 51.2.

( , ) watts

(d) Compute an 82% CI for μ when n = 100 and x = 51.2

( , ) watts

(e) How large must n be if the width of the 99% interval for μ is to be 1.0? (Round your answer up to the nearest whole number.)

n=

You may need to use the appropriate table in the Appendix of Tables to answer this question.

Answer 1

a)

b)

c)

d)

e) Given

The width of the 99% interval for μ is to be 1.0