Travelocity would like to estimate the current average domes

Travelocity would like to estimate the current average domestic airfare. The following data show the airfares for 24 randomly selected tickets for travel within the United States: $356 $275 $371 $384 $457 $326 $414 $367 $362 $286 $104 $136 $320 $244 $370 $215 $322 $409 $303 $489 $251 $361 $337 $265 Construct a 95% confidence interval with these data to estimate the average domestic airfare. Write you answer in the interval notation: \"(lowerbound, upperbound)\"

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)=321.83
Standard deviation( sd )=90.662
Sample Size(n)=24
Confidence Interval = [ 321.83 ± t a/2 ( 90.662/ Sqrt ( 24) ) ]
= [ 321.83 - 2.0687 * (18.506) , 321.83 + 2.0687 * (18.506) ]
= [ 283.546,360.114 ]