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

  b.   the average rate of change of f(x) is less than the average rate of change of g(x).

step-by-step explanation:

since the length of the interval is the same in each case, we only need to compare the change in y-value to see which is greater.

so the change in y-value for function f is (6 )) = 9.

the table tells us

so the change in y-value for function g is (31 -1) = 30.

the change in y-value of f(x) on the interval is less than the change in y-value of g(x) on the same interval, so the average rate of change of f(x) is less than the average rate of change of g(x).

answer: d. $20

step-by-step explanation:

just took the test