A TV advertisement was shown for a total of 30 times. After which it has been found out that the sales of the advertised product had a mean of Php100, 000 a week with the standard deviation of...

A TV advertisement was shown for a total of 30 times. After which it has been found out that the sales of the advertised product had a mean of Php100, 000 a week with the standard deviation of Php75,000 1. What is the probability that the sample mean belongs to Php90,000 to Php110,000? 2. What is the Interval if the mean sale covers the middle 95% of the distribution of the sample mean?