Final answer:
A t-distribution is used because the sample size is small and the population standard deviation is unknown. A one-sample t-test is conducted to see if the sample supports the travel agency's claim at the 5% level, but actual calculations are needed to determine this definitively.
Step-by-step explanation:
When testing the travel agency's claim regarding holiday satisfaction scores, the appropriate distribution to use is a t-distribution. This is because the sample size is less than 30, and the population standard deviation is unknown. In testing at the 5% significance level (alpha = 0.05), the t-distribution provides a way to account for increased variability that comes with estimating the population standard deviation using a small sample.
To determine whether the sample supports the agency's claim at the 5% level, a one-sample t-test is conducted. If the t-statistic calculated falls within the critical values for a t-distribution with n-1 degrees of freedom, and the p-value associated with the t-statistic is greater than 0.05, the null hypothesis that the mean satisfaction score is less than or equal to 9 is not rejected. In this case, the sample would support the agency's claim. However, the actual calculations, including the resulting t-statistic and p-value, should be provided to make a definitive statement on support for the claim. Without these calculations, we cannot conclude the level of support the sample provides for the claim.