A recent study of 25 students showed that they spend an average of $18.53 for gas per week. The sample standard deviation was $3.00, and the sample distribution was approximately normal. If we were to find a 95% confidence interval for the true mean, it would be
Question 19 options:
a confidence interval for the mean using a table value from the standard normal distribution.
a confidence interval for the mean using a table value from the t distribution.
a confidence interval for a proportion using a table value from the standard normal distribution.
a confidence interval for proportion using a table value from the t distribution.
none of the other answers are correct.
The correct answer is: a confidence interval for the mean using a table value from the t distribution.
This is because the sample size is small (25 students) and the population standard deviation is unknown. In this case, we use the t-distribution instead of the standard normal distribution.