The mean of a normally distributed dataset is 12, and the standard deviation is 2.

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

Could someone with number 1 and 2

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?