Question

General Instructions: Any hypothesis test should have five parts as illustrated in the examples in your textbook. Clearly identify each part.

1. GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.50 mg of mercury. Historical data reveal a standard deviation of 0.18 mg, based upon years of production records. A random sample of 24 bulbs has a mean of 3.62 mg of mercury. If we give the benefit of the doubt to GreenBeam:

(a) test whether or not we should believe the manufacturer’s claim. Use a 1% significance level.

(b) Find the p-value for this test.

Answer 1

a)

H0 : mu = 3.5
Ha : mu < 3.5

test statistics:

t = ( x -mean)/(s/sqrt(n))
= ( 3.62 - 3.5)/(0.18/sqrt(24))
= 3.2660

b)
p value = .0017

Reject Ho