Question

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?

Answer 1

Answer:

74.72

Step-by-step explanation:

Given

mean$\left ( \mu \right )=70$

Standard deviation $\left ( \sigma \right )=7$

For Top 25%

$P\left ( Z$

and Z value for 75 % is 0.6744

Thus score which separates the Top 25% of students is

$=\mu +\sigma \cdot Z$

$=70+7\cdot 0.6744=74.7208$