State Ho Ha the claim show the graph display the confidence

State Ho & Ha, the claim, show the graph, display the confidence interval, & make an interpretation.

A fast food outlet claims that the mean waiting time in line is less than 3.5 minutes. A random sample of 60 customers has a mean of 3.6 minutes with a standard deviation of 0.6 minute. If a=0.05, test the food outlet\'s claim using confidence intervals.

Solution

CI = x ± t a/2 * (sd/ Sqrt(n))
Where,
x = Mean
sd = Standard Deviation
a = 1 - (Confidence Level/100)
ta/2 = t-table value
CI = Confidence Interval
Mean(x)=3.6
Standard deviation( sd )=0.6
Sample Size(n)=60
Confidence Interval = [ 3.6 ± t a/2 ( 0.6/ Sqrt ( 60) ) ]
= [ 3.6 - 2.001 * (0.077) , 3.6 + 2.001 * (0.077) ]
= [ 3.445,3.755 ]

We don\'t have enough evidence to support fast food outlet claims that the mean waiting time in line is less than 3.5 minutes