The number of cell phones per 100 residents in countries in Europe is given in the first table. The numberof cell phones per 100 residents in countries of the Americas is given in the second table. Find the 90%confidence interval for the difference in mean number of cell phones per 100 residents in Europe and theAmericas. We assume the variances are not equal. Round to the nearest whole number.Number of Cell Phones per 100 Residents in Europe130136 130 66 1326993105 11256102861031221274496 45113101109109 7411270 1001021249862 37 1032319496 135 103 99 109 99 13015187134 79108 59 785590 123 56Number of Cell Phones per 100 Residents in the Americas106 38937192 42104158 1099510890 78 1654499 12794 119 989310412578483345109109 13911946117824890264760Withper 100 residents in Europe and the Americas is between% confidence, it can be said that the difference in mean number of cell phonesand

Obtain the 90% confidence interval for the difference in mean number of cell phones per 100 residents in Europe and the Americas. The 90% confidence interval for the difference in mean number of cell phones per 100 residents in Europe and the Americas is obtained below as follows: The formula for two sample t-test confidence interval is, Use EXCEL Procedure for finding the values of mean and the variance for both the samples. Follow the instruction to obtain the values of mean and SD: Open EXCEL Go to Data>Data Analysis. Choose Descriptive Statistics. Enter the input range as $A$1:$B$54. Check the Labels in the first row. Check the option Summary statistics Click OK. EXCEL output: From EXCEL output, The value of mean for Europe is 97.6226. The value of variance for Europe is 998.7779349 The value of mean for America is 88.3846. The value of variance for America is 1177.19 Obtain the degrees of freedom. The degrees of freedom formula for unequal variance is: The required value is, Thus, the degrees of freedom is 78. Use EXCEL Procedure for finding the critical value of t. Follow the instruction to obtain the critical value of t: Open EXCEL Go to Formula bar. In formula bar enter the function as“=TINV” Enter the probability as 0.10 Enter the degrees of freedom as 78. Click enter EXCEL output: From the EXCEL output, the critical value of t at 0.10 level of significance with the 78 degrees of freedom is 1.66463 The required confidence interval is, With 90% confidence, it can be said that the difference in mean number of cell phones per 100 residents in Europe and Americas is between –2 and 21.