In: Statistics and Probability
In a survey of 3929 travelers, 1431 said that location was very important for choosing a hotel and 1222 said that reputation was very important in choosing an airline. Complete parts (a) through (c) below.
a. Construct a 95% confidence interval estimate for the population proportion of travelers who said that location was very important for choosing a hotel.
b. Construct a 95% confidence interval estimate for the population proportion of travelers who said that reputation was very important in choosing an airline.
Total number of travelers = n = 3929
x1 = total number of travelers who said that location was very important for choosing a hotel =1431
x2 = total number of travelers who said that reputation was very important in choosing an airline = 1222
a. Construct a 95% confidence interval estimate for the population proportion of travelers who said that location was very important for choosing a hotel.
The formula of confidence interval for the population proportion is as follow:
Where E is the margin of error:
The formula of E is as follow:
Here = x1 / n = 1431 / 3929 = 0.3642
Let's find the value of in excel:
Plug all the required values in the formula of E, we get
So that ,
Lower limit = - E = 0.3642 - 0.0150= 0.3492
Upper limit = + E = 0.3642 + 0.0150= 0.3792
The 95% confidence interval estimate for the population proportion of travelers who said that location was very important for choosing a hotel is ( 0.3492, 0.3792)
b. Construct a 95% confidence interval estimate for the population proportion of travelers who said that reputation was very important in choosing an airline.
Here = x2 / n = 1222 / 3929 = 0.3110
Lower limit = - E = 0.3110 - 0.0145= 0.2965
Upper limit = + E = 0.3110 + 0.0145 = 0.3255
The 95% confidence interval estimate for the population proportion of travelers who said that reputation was very important in choosing an airline is ( 0.2965, 0.3255).