Question

Lexie scores an average of 527 points in a pinball game, and her points in a pinball game are normally distributed. Suppose Lexie scores 471 points in a game, and this value has a z-score of −2. What is the standard deviation? Do not include the units in your answer. For example, if you found that the standard deviation was 10 points, you would enter 10

Answer 1

Answer:  28 points

Step-by-step explanation:

Given : Lexie scores an average of $\mu=527$  points in a pinball game, and her points in a pinball game are normally distributed.

Let x be the random variable that represents the  her points in a pinball game.

$z=\dfrac{x-\mu}{s}$, where s is the standard deviation.

Lexie scores 471 points in a game, and this value has a z-score of −2.

i.e. $-2=\dfrac{471-527}{s}$

$-2s=-56\\\\\Rightarrow\ s=\dfrac{56}{2}=28$

Hence, the standard deviation= 28 points