The slope of this line is positive
This is a parabola which looks like an inverted U. Its will have a maximum value when t = 7 as we see from the vertex form below:-
- t^2 + 14t - 40
= - ( t - 7)^2 + 49 - 40
= -(t - 7)^2 + 9
There is an axis of symmetry at x = 7.
so a is true since 7 is the maximum value of the function and its less at t = 6.
c is also true because of the symmetry about t = 7
Answer:
It landed at a height of 14 feet
Step-by-step explanation:
Given
--- Path of a t-shirt
--- height of bleachers
Required
Height when t-shirts land in bleachers
Make y the subject
Substitute in
Multiply through by 24
Express as:
Using a calculator:
or
x can not be negative:
So:
Substitute in to calculate the height it landed
Answer:
Almost 2.5% of the students spent more than $275 in a semester.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 235
Standard deviation = 20
According to the standard deviation rule, almost 2.5% of the students spent more than what amount of money on textbooks in a semester?
95% of the measures are within 2 standard deviation of the mean. The other 5% are more than 2 standard deviations of the mean. Since the normal distribution is symmetric, 2.5% of those are below two standard deviations of the mean and 2.5% are more than two standard deviations above the mean.
235 + 2*20 = $275
Almost 2.5% of the students spent more than $275 in a semester.