Consumption of alcoholic beverages by young women of drinkin

Consumption of alcoholic beverages by young women of drinking age has been increasing in the United Kingdom, The United State, and Europe (The Wall Street Journal, February 15, 2006). Data (annual consumption in liters) consistent with the findings reported in The Wall Street Journal article are shown for a sample of 20 European young women

266 82 199 174 97

170 222 115 130 169

164 102 113 171 0

93 0 93 110 130

Assuming the population is roughly symmetric, construct a 95% confidence interval for the mean annual consumption of alcoholic beverages by European young women

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)=130
Standard deviation( sd )=65.9113
Sample Size(n)=20
Confidence Interval = [ 130 ± t a/2 ( 65.9113/ Sqrt ( 20) ) ]
= [ 130 - 2.093 * (14.738) , 130 + 2.093 * (14.738) ]
= [ 99.153,160.847 ]