Q:

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

Accepted Solution

A:
Answer:  28 pointsStep-by-step explanation:Given : Lexie scores an average of [tex]\mu=527[/tex]  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.[tex]z=\dfrac{x-\mu}{s}[/tex], where s is the standard deviation.Lexie scores 471 points in a game, and this value has a z-score of −2.i.e. [tex]-2=\dfrac{471-527}{s}[/tex][tex]-2s=-56\\\\\Rightarrow\ s=\dfrac{56}{2}=28[/tex]Hence, the standard deviation= 28 points