Use this information below to answer questions 121-122.
A researcher looked at young people's Knowledge of the cost of weddings, where it's been found that many students' estimates of the cost of a wedding was less than the actual average. As a result of this finding, imagine you hypothesize that young people will underestimate the average cost of a wedding gown. To test this hypothesis, a group of college students are asked, "According to the Brides.com ( HYPERLINK "http://www.brides.com/" http://www.brides.com) 2009 American Wedding Survey, what is the average cost of a wedding gown?" The responses of some of the students in this class are summarized as:
N = 28 = 2432.14
s = 1643.18
-For α = .05 (two-tailed), which of the following is an appropriate critical value?
A) 1.703
B) 1.706
C) 2.052
D) 2.056

Question

Use this information below to answer questions 121-122.
A researcher looked at young people's Knowledge of the cost of weddings, where it's been found that many students' estimates of the cost of a wedding was less than the actual average. As a result of this finding, imagine you hypothesize that young people will underestimate the average cost of a wedding gown. To test this hypothesis, a group of college students are asked, "According to the Brides.com ( HYPERLINK "http://www.brides.com/" http://www.brides.com) 2009 American Wedding Survey, what is the average cost of a wedding gown?" The responses of some of the students in this class are summarized as:
N = 28  = 2432.14
s = 1643.18
-For α = .05 (two-tailed), which of the following is an appropriate critical value?
A) 1.703 
B) 1.706 
C) 2.052 
D) 2.056

Quizplus · Accepted Answer

Since the sample size is less than 30 and the population standard deviation is unknown, we need to use a t-distribution. The degrees of freedom for this problem are 27 (n-1 = 28-1). Looking up the critical value for a two-tailed t-test with α = .05 and 27 degrees of freedom in a t-table, we get 2.052. Therefore, C is the correct answer.

Use This Information Below to Answer Questions 121-122