Answer:
y + 20 = 9(x + 2)
Step-by-step explanation:
The equation of a line in point- slope form is
y - b = m(x - a)
where m is the slope and (a, b) a point on the lie
Calculate m using the slope formula
m = (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (- 2, - 20) and (x₂, y₂ ) = (9, 79)
m = =
= 9
Using (a, b) = (- 2, - 20), then
y - (- 20) = 9(x - (- 2)), that is
y + 20 = 9(x + 2)
Answer: c)[50,60]
Step-by-step explanation:
The Empirical rule says that , About 68% of the population lies with the one standard deviation from the mean (For normally distribution).
We are given that , The heights of students in a class are normally distributed with mean 55 inches and standard deviation 5 inches.
Then by Empirical rule, about 68% of the heights of students lies between one standard deviation from mean.
i.e. about 68% of the heights of students lies between
i.e. about 68% of the heights of students lies between
Here,
i.e. The required interval that contains the middle 68% of the heights. = [50,60]
Hence, the correct answer is c) (50,60)