Josh paid for three books with two $20 bill .he received $1in change each book was the same price .how much did each book cost ?

The total payment is:
 P = 2 * ($ 20) = $ 40
 The change is:
 C = 1 $
 The total cost is then:
 CT = P-C = 40 $ -1 $ = 39 $
 "each book was the same price":
 Book price = ($ 39/3) = $ 13
 
 each book cost:
 Book price = 13 $

Horizontal axis with 1, 2, and 3 standard deviations above the mean are 51.6, 56.2, 60.8

Horizontal axis with 1, 2, and 3 standard deviations below the mean are 42.4, 37.8, 33.2

Step-by-step explanation:

A data set has a normal distribution with a mean of 47 and a standard deviation of 4.6

Mean, M ⇒ 47Standard deviation ⇒ 4.6

From this information, you have to scale the horizontal axis with the mean of this distribution and values at 1, 2, and 3 standard deviations above and below the mean.

Horizontal axis with 1, 2, and 3 standard deviations above the mean :

1 standard deviation above the mean ⇒ M + SD

⇒ 47 + 4.6 = 51.6

2 standard deviations above the mean ⇒ M + 2SD

⇒ 47 + (2 × 4.6) = 56.2

3 standard deviations above the mean ⇒ M + 3SD

⇒ 47 + (3 × 4.6) = 60.8

Horizontal axis with 1, 2, and 3 standard deviations below the mean :

1 standard deviation below the mean ⇒ M - SD

⇒ 47 - 4.6 = 42.4

2 standard deviations below the mean ⇒ M - 2SD

⇒ 47 - (2 × 4.6) = 37.8

3 standard deviations below the mean ⇒ M - 3SD

⇒ 47 - (3 × 4.6) = 33.2