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GarryVolchara [31]
2 years ago
5

The scores on a math test are normally distributed with a mean of 74 and a standard deviation of 8. The test scores range from 0

to 100. Seven students had test scores between 82 and 98. Estimate the number of students who took the test.
Mathematics
1 answer:
hram777 [196]2 years ago
7 0

Answer:

The Estimate the number of students who took the scores between  82 and 98 = 16

Step-by-step explanation:

<u><em>Explanation</em></u>:-

Given data The scores on a math test are normally distributed with a mean μ = 74  

standard deviation of Population

                                               S.D (σ) = 8

Let 'x' be the random variable of Normal distribution

<u><em>case(i)</em></u>:-  when  x = 82

            Z = \frac{x-mean}{S.D}

           Z = \frac{82-74}{8} = 1

     

<u><em>case(ii)</em></u>:-  when  x = 98

            Z = \frac{x-mean}{S.D}

           Z = \frac{98-74}{8} = 3

The probability that test scores between 82 and 98.

P(82≤x≤98) = P(1≤z≤3)

                 = P(z≤3) - P(z≤1)

                 = 0.5+A(3)-(0.5+A(1))

                =  A(3) -A(1)

               = 0.4986 - 0.3413

               = 0.1573

<u><em>Final answer</em></u>:-

The Estimate the number of students who took the scores between  82 and 98

             = 100 X 0.1573 = 15.73 ≅16

           

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