Answer:
38.11%
Step-by-step explanation:
Given that:
Mean (μ) = 75, standard deviation (σ) = 5
Z score is a measure in statistics to determine the variation of a raw score from the mean. It is given by the equation:
[tex]z=\frac{x-\mu}{\sigma}[/tex]
To calculate the percentage of students scored between a 73 and 78 (C grade), we need to find the z score for 73 and then for 78.
For x = 73, the z score is:
[tex]z=\frac{x-\mu}{\sigma}=\frac{73-75}{5} =-0.4[/tex]
For x = 78, the z score is:
[tex]z=\frac{x-\mu}{\sigma}=\frac{78-75}{5} =0.6[/tex]
From the probability distribution table:
P(73 < x < 78) = P(-0.4 < z < 0.6) = P(z < 0.6) - P(z < -0.4) = 0.7257 - 0.3446 = 0.3811 = 38.11%