“A machine is designed to fill jars with 16 ounces of coffee. A consumer suspect

Question

“A machine is designed to fill jars with 16 ounces of coffee. A consumer suspects that the machine is not filling the jars completely. A sample of 8 jars has a mean of 15.6 ounces and a standard deviation of 0.3 ounce. Is there enough evidence to support the consumer’s conjecture at = 0.05?”

a) First, identify the alternative and the null hypotheses.
b) Secondly, calculate the critical value and df.
c) Next, use the appropriate formula.
d) Finally, decide whether or not to reject the null hypothesis.

Explanation / Answer

Given n=8, xbar=mean=15.6, s=0.3

=0.05, the critival value is |t(0.025,df=n-1=7)|=2.364 (check student t table)

------------------------------------------------------------------------------------------------------------

The test hypothesis is

Ho:=16

Ha: not equal 16

The test statistic is

t=(xbar-)/(s/n)

=(15.6-16)/(0.3/sqrt(8))

= -3.77

Since t= -3.77 < -2.364, we reject Ho. So there is enough evidence to support the consumer’s conjecture at = 0.05.

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.