Question

The Carolina Tobacco Company advertised that its bestselling non-filtered cigarettes contain 40 milligrams of nicotine. Consumer Advocate magazine ran tests of n = 10 randomly selected cigarettes and found that sample mean and standard deviation were ¯x = 43.3 milligrams and s = 6.8 milligrams of nicotine, respectively

(a) At 5% significance level test hypotheses to determine whether the mean nicotine content is greater than 40 milligrams.

(b) Interpret your answer from part (a).

Answer 1

Solution :

Given that,

= 43.3

s = 6.8

n = 10

a.) Hypothesis:

H0 : 40

Ha :   40

Test Statistic:

t = ( - ) / (s /n)

t = (43.3 - 40 ) / ( 6.8 / 10 )

t = 1.535

P - value = 0.0796

if P- value < 0.05 then reject H0.

P-value > 0.05, we Fail to reject H0.

the mean nicotine content is not greater than 40 milligrams.