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

Answer:

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

8 0

3 years ago

jamal completed his math homework in 2/3 of an hour and his reading homework in 3/5 of an hour. How much time did it take him to

Assoli18 [71]

Answer:

Step-by-step explanation: We have to add how much time it took him to do all of his homework. To do this, we have to add 2/3 and 3/5.

First, we have to find a LCM between 3 and 5.

The LCM between those numbers are 15.

Next we find out what number to multiply 3 by to get 15, we multiply it by 5.

2 * 5 = 10

3 * 5 = 15

Next we find out what number to multiply 5 by to get 15, we multiply it by 3.

3 * 3 = 9

5 * 3 = 15

10/15+9/15=19/15

We are left off with 1 4/15

So it took him 1 hour and 4/15 minutes to do his homework.

3 0

3 years ago