A university research team is studying the average height of a particular species of tree in a forest. They report the mean height and a 95%95\% confidence interval for each year of their study. In the fifth year, the confidence interval for the mean height is much wider than in the previous four years. Which of the following is the most likely reason for the wider confidence interval in the fifth year?

Fewer trees were measured in the fifth year.

The mean tree height was lower in the fifth year.

The measuring equipment was more accurate in the fifth year.

The confidence level was decreased in the fifth year.

A university research team is studying the average height of a pa...

Confidence Intervals for Population Mean: Videos & Practice Problems