Question

IQ scores have a population mean mu = 100 and a population standard deviation sigma = 15 . Convert the following standard z interval val, z <= 2.58 , to an x interval .

Answer 1

we get that

`Z=(x-\mu)/(\sigma)\rightarrow x=\sigma\cdot Z+\mu=15\cdot2.58+100=138.7`

so the interval is

`X\le138.7`