A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20

Complete Question

A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20. What proportion of wand prices are lower than the price of the blackthorn wand? You may round your answer to four decimal places

0.1151

Step-by-step explanation:

We solve using z score formula

z = (x-μ)/σ, where

x is the raw score = $45.20

μ is the population mean = $50

σ is the population standard deviation = $4

We are solving for x < 45.20

Hence:

z = 45.20 - 50/4

z = -1.2

Probability value from Z-Table:

P(x<45.20) = 0.11507

Approximately to 4 decimal places = 0.1151

Therefore, the proportion of wand prices that are lower than the price of the blackthorn wand is 0.1151

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart