In: Statistics and Probability
The cost of weddings in the United States has skyrocketed in recent years. As a result, many couples are opting to have their weddings in the Caribbean. A Caribbean vacation resort recently advertised in Bride Magazine that the cost of a Caribbean wedding was less than $10,000. Listed below is a total cost in $000 for a sample of 8 Caribbean weddings. At the 0.025 significance level is it reasonable to conclude the mean wedding cost is less than $10,000 as advertised? 12.4 8.5 10.1 12.6 10.5 9.1 9.8 11.2
a. State the null hypothesis and the alternate hypothesis. Use a .025 level of significance. (Enter your answers in thousands of dollars.) H0: μ ≥ H1: μ <
b. State the decision rule for 0.025 significance level. (Negative amount should be indicated by a minus sign. Round your answer to 3 decimal places.) Reject H0 if t <
c. Compute the value of the test statistic. (Negative amount should be indicated by a minus sign. Round your answer to 3 decimal places.) Value of the test statistic
d. What is the conclusion regarding the null hypothesis? H0. The cost is than $10,000.
(a)
Ho: ≥ 10000
Ha: < 10000
The Null hypothesis states that the mean wedding cost in Carribbean is greater than or equal to 10000
Alternative hypotheiss states that the mean wedding cost in Caribbean is less than 10000.
(b) Decision rule :
level of significance is 0.025
If p value is ≤ 0.025, we reject the Null hypothesis.
If p value is > 0.025, we fail to reject the Null hypothesis.
t critical at df = 7 , level of significance = 0.025
Reject Ho: If t stat < t critical (- 2.365)
Fail to reject Ho: If t stat > t ciritical ( -2.365)
(C) Test statistics
n = 8
sample mean = sum of all terms / no of terms = 84200 /8 = 10525
sample sd = s
data | data-mean | (data - mean)2 |
12400 | 1875 | 3515625 |
8500 | -2025 | 4100625 |
10100 | -425 | 180625 |
12600 | 2075 | 4305625 |
10500 | -25 | 625 |
9100 | -1425 | 2030625 |
9800 | -725 | 525625 |
11200 | 675 | 455625 |
Assuming that the data is normally distributed and also as the population sd is not given, we will calculate t stat
t = 1.011
(d)
p value = TDIST (t statistics, df, tails) = TDIST (1.011, 7,1) = 0.1729
As the p value (0.1729) is > 0.025, we fail to reject the Null hypothesis.
As the t stat (1.011) > t critical (-2.365), we fail to reject the Null hypothesis.
Hence, we do not have sufficient evidence to believe that the mean wedding cost is Carribean is less than 10000.