GreenBeam Ltd claims that its compact fluorescent bulbs aver

GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.29 mg of mercury. A sample of 25 bulbs shows a mean of 3.36 mg of mercury. (a) State the hypotheses for a right-tailed test, using GreenBeam\'s claim as the null hypothesis about the mean. (b) Assuming a known standard deviation of 0.21 mg, calculate the z test statistic to test the Manufacturer\'s claim. (Round your answer to 2 decimal places.) (d) Find the p-value. (Round your answer to 4 decimal places.)

Solution

(a)Ho: mu<=3.29 mg v.s. H1: mu>3.29 mg

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(b) The test statisitc is

Z=(xbar-mu)/(s/vn)

=(3.36-3.29)/(0.21/sqrt(25))

=1.67

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(d) So the p-value= P(Z>1.67) =0.0475 (from standard normal table)