Question

For the following, conduct a hypothesis test using the p-value or critical value method.

Find and state: a) H₁ or H_0, as requested, b) z_c or t_c value as appropriate c) z or t value as appropriate d) the interpreted answer to the question.

9. The S-Tepp Light Bulb Company claims the mean life of a certain type of bulb more than 2500 hours, with a population standard deviation of 400 hours. Tonia’s random sample of 182 bulbs has a mean life of 2525 hours. Does Tonia’s test support S-Tepp’s claim at α = 0.07?

a) H₁__________ b) __________ c) __________ d) ________________________________

Answer 1

Answer:

= 2500,   = 400

n= 182 , = 2525

= 0.07,  

a)

null and alternative hypothesis is

Ho:   2500

H1:   > 2500

b)

calculae z criical value for right tailed test with = 0.07

we get critical value as

Zc = 1.48

c)

formula for test statistics is

z = 0.84317

Z = 0.84317

d)

Decision rule is

Reject Ho if ( Z )  ( Zc )

here, ( Z = 0.84317 ) < ( Zc = 1.48 )

Hence,

Null hypothesis is NO rejected.

Therefore there is not sufficient evidence to support the claim of S-Tepp Light Bulb Company  that the mean life of a certain type of bulb are more than 2500 hours.