Answer:
Step-by-step explanation:
[tex]H_0: xbar = 12\\H_a: x bar \neq 12[/tex]
(Two tailed test at 0.05 significance level)
Given that sample parameters are(Mean =12.1,s= 0.5)
Since population std deviation is not known only t test can be used.
Mean difference = 12.1-12 =0.1
Std error = [tex]\frac{0.5}{\sqrt{49} } =0.071[/tex]
Test statistic t = mean diff/se = 1.41
df =49-1 =48
p value = 0.1649
Since p >0.05 we accept null hypothesis.
There is evidence to confirm that the production line is really producing rulers that are 12 inches long