Question

When people smoke, the nicotine they absorb is converted to cotinine, which can be measured.A random sample of 40 smokers has a mean cotinine level of 172.5 ng/ml with a sample standard deviation of 119.5 ng/ml. Use a 0.05 significance level to test the claim that the mean cotinine level of smokers is equal to 200ng/ml.

H0: μ___200 For Q23(circle one: equal to, less than , greater than, not equal to)

H1: μ___200 For Q24 (circle one:equal to, less than, greater than, not equal to)

Test Statistic t=__________ Q25 (ROUND TO 2 DECIMAL PLACES)

P-value: p =_____________ Q26 (ROUND TO4 DECIMAL PLACES)

Decision:________________________Q27 (circle one:Reject H0 , Fail to Reject H0)

Conclusion:_________________________________________________________

Q28 Circle one for the conclusion:

There is sufficient evidence to warrant the rejection of the claim.

OR

There is not sufficient evidence to warrant the rejection of the claim

Answer 1

Solution :

= 200

= 172.5

s =119.5

n = 405

This is the two tailed test .

The null and alternative hypothesis is ,

H0 :    = 200

Ha :     200

Test statistic = t

= ( - ) / s / n

= ( 172.5- 200) /119.5 / 40

= -1.455

Test statistic = t = -1.455

P-value =0.1535

= 0.05  

P-value >

0.1535 > 0.05

Fail to reject the null hypothesis .

There is not sufficient evidence to warrant the rejection of the claim