HEB grocery wants to estimate the average transaction amount ($) for purchases. They know this is likely to vary by day of week, so they first look at transactions on Mondays. They know that the population standard deviation for their Monday transactions is $8.20.

From their computer records they found that for 2,860 transactions on previous Mondays, the sample average was $21.55. Purchase transaction amounts can be any fractional dollar value.

Interpret the answer to the previous question where you found the 85%confidence interval.

15% of transaction amounts on Mondays typically are in error

85% probability that the average transaction amounts on Mondays is in this range.

85% of all Monday transaction amounts in the past were in this range.

85% of all transaction amounts on Monday are predicted to be in this range.

85% probability that the average transaction amount on Mondays for the previous 2,860 Mondays is in this range