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The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution, what test score separates the top 25% of the students from the lower 75% of students?

Respuesta :

Answer:

74.72

Step-by-step explanation:

Given

mean[tex]\left ( \mu \right )=70[/tex]

Standard deviation [tex]\left ( \sigma \right )=7 [/tex]

For Top 25%

[tex]P\left ( Z<z\right )=0.75[/tex]

and Z value for 75 % is 0.6744

Thus score which separates the Top 25% of students is

[tex]=\mu +\sigma \cdot Z[/tex]

[tex]=70+7\cdot 0.6744=74.7208[/tex]

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