Question

2. The average daily volume for Singpost is normally distribution with a mean of 7,000,000 and standard deviation of 800,000 packages per day. What proportion of the days was the volume between 6,000,000 and 6,500,000 packages?

Answer 1

by table or by ti83?

Answer 2

by formula

Answer 3

well, we can determine z scores, then either look in a table to see how those scores are defined and do some algebra, or we can insert this into a statistics calculator.program.

these days, they tend to teach this stuff using the calculator/program

Answer 4

\[z = \frac{x-\bar x}{\sigma}\]