Question

Many couples believe that it is getting too expensive to host an "average" wedding in the United States. According to the website www.costofwedding, the average cost of a wedding in the U.S. in 2009 was $24,066. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of a wedding was $23,224, with a standard deviation of $2,903. On the basis of this, a 95% confidence interval for the mean cost of weddings in the U.S. is $22,296 to $24,152.

Answer 1

Explanation:

Given that many couples believe that it is getting too expensive to host an "average" wedding in the United States.

Population mean =24066

Sample mean = 23224

Sample size = 40

Sample std dev = 2903

Since sample std dev is known, we use t critical value.

df =39

Sample mean follows a normal distribution with mean = 23224, and std dev =
`(s)/(√(n) ) \\=(2903)/(√(40) ) \\=459.005`

t critical value = 2.023

Margin of error = 2.023*459.005

Confidence interval
`(22295.43, 24152.57)`