Using the vertex of the quadratic function, it is found that:
a) The maximum number of customers in the store is at 12 P.M.
b) 75 customers are in the store at this time.
The number of customers in x hours after 7 AM is given by:
Which is a quadratic equation with coefficients 
Item a:
The maximum value, considering that a < 0, happens at:
Hence:
5 hours after 7 A.M, hence, the maximum number of customers in the store is at 12 P.M.
Item b:
The value is y(5), hence:
75 customers are in the store at this time.
A similar problem is given at brainly.com/question/24713268
Answer:
x = friends that paid discount price = 8
y = friends that paid regular price = 4
Step-by-step explanation:
Let
x = friends that paid discount price
y = friends that paid regular price
x + y = 12 (1)
6x + 8y = 80 (2)
From (1)
x = 12 - y
Substitute x = 12 - y into (2)
6x + 8y = 80 (2)
6(12 - y) + 8y = 80
72 - 6y + 8y = 80
- 6y + 8y = 80 - 72
2y = 8
y = 8/2
y = 4
Substitute y = 4 into (1)
x + y = 12 (1)
x + 4 = 12
x = 12 - 4
x = 8
x = friends that paid discount price = 8
y = friends that paid regular price = 4
So we are given the mean and the s.d.. The mean is 100 and the sd is 15 and we are trying the select a random person who has an I.Q. of over 126. So our first step is to use our z-score equation:
z = x - mean/s.d.
where x is our I.Q. we are looking for
So we plug in our numbers and we get:
126-100/15 = 1.73333
Next we look at our z-score table for our P-value and I got 0.9582
Since we are looking for a person who has an I.Q. higher than 126, we do 1 - P. So we get
1 - 0.9582 = 0.0418
Since they are asking for the probability, we multiply our P-value by 100, and we get
0.0418 * 100 = 4.18%
And our answer is
4.18% that a randomly selected person has an I.Q. above 126
Hopes this helps!
Answer:
x = - 100
Step-by-step explanation:
Given
+ 6 = - 14 ( subtract 6 from both sides )
= - 20
Multiply both sides by 5 to clear the fraction
x = 5 × - 20 = - 100
