Welcome to Westonci.ca, where your questions are met with accurate answers from a community of experts and enthusiasts. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields. Get precise and detailed answers to your questions from a knowledgeable community of experts on our Q&A platform.

The diameter of cork of a Champagne bottle is supposed to be 1.5 cm. If the cork is either too large or too small, it will not fit in the bottle. The manufacturer measures the diameter in a random sample of 36 bottles and finds their mean diameter to be 1.4 cm with standard deviation of 0.5 cm. Is there evidence at 1% level that the true mean diameter has moved away from the target?

Sagot :

Answer:

[tex]t_{n-1,\alpha/2}=3.59114678[/tex]

Therefore we do not have sufficient evidence at [tex]1\%[/tex] level that the true mean diameter has moved away from the target

Step-by-step explanation:

From the question we are told that:

Sample size [tex]n=36[/tex]

Mean diameter [tex]\=x=1.4[/tex]

Standard deviation [tex]\sigma=0.5cm[/tex]

Null hypothesis [tex]H_0 \mu=1.5[/tex]

Alternative hypothesis [tex]\mu \neq 1.5[/tex]

Significance level [tex]1\%=0.001[/tex]

Generally the equation for test statistics is mathematically given by

[tex]t=\frac{\=x-\mu}{\frac{s}{\sqrt{n} } }[/tex]

[tex]t=\frac{1.4-1.5}{\frac{0.5}{\sqrt{36} } }[/tex]

[tex]t=-1.2[/tex]

Therefore since this is a two tailed test

[tex]t_{n-1,\alpha/2}[/tex]

 Where

   [tex]n-1=36-1=>35[/tex]

   [tex]\alpha=/2=0.001/2=>0.0005[/tex]

From table

[tex]t_{n-1,\alpha/2}=3.59114678[/tex]

Therefore we do not have sufficient evidence at [tex]1\%[/tex] level that the true mean diameter has moved away from the target