Question

A certain type of stainless steel powder is supposed to have a mean particle diameter of μ = 15 μm. A random sample of 86 particles had a mean diameter of 15.2 μm, with a standard deviation of 1.8 μm. A test is made of H0 : μ = 15 versus H1 : μ ≠ 15.

Find the P-value. Round the answer to four decimal places.

Numeric Response

Answer 1

SOLUTION

this is the two tailed test .  

The null and alternative hypothesis is ,

H0 :   = 15

Ha :     15

Test statistic = z

= ( - ) / / n

= (15.2-15) / 1.8 / 86

= 1.03

P(z >1.03 ) = 1 - P(z < 1.03 ) = 1-0.8485=0.1515 USING Z TABLE

P-value =0.1515