You're looking for a value

such that

Because the distribution is symmetric, the value of

in either case will be the same.
Now, because the distribution is continuous, you have that

The mean for the standard normal distribution is

, and because the distribution is symmetric about its mean, it follows that

.

You can consult a

score table to find the corresponding score for this probability. It turns out to be

.
4.4 is the answer for that problem 17.6 divided by 4
It’s a frequency table, you find the middle number from the prices of mail received and you would multiply it. Not sure what with but if you search on Google Frequency tables there should be a good explanation.
Hope this helped you!
V + 6 < 7
subtract 6 from both sides:-
V < 7 - 6
V < 1
The correct answer to that question is T = 12