Write the Word or Phrase That Best Completes Each Statement

Write the word or phrase that best completes each statement or answers the question.
-Suppose that you wish to obtain a 95% confidence interval for a population mean. The population is normally distributed, the sample size is 20, and the population standard deviation is unknown. The correct procedure to use is the t-interval procedure. If you mistakenly use the z-interval procedure, will the resulting confidence interval be too wide or too narrow? Will the true confidence level associated with this interval be greater than or less than 95%?