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:

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:

For x = 78, the z score is:

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%
Slope = (y2 - y1)/(x2 - x1)
slope = (-3 -4)/(1 - 1)
slope -7/0
This is an undefined slope because the denominator is 0.
This would be a vertical line.