(x+4)^2 / 9 - (y+3)^2 / 16 = 1
a^2 = 16 and b^2 = 9
a = +4 and -4
b = +3 and -3
Center is (-4, -3)
Vertices is (-4 + a, -3) and (-4 - a, -3)
Vertices is (-1, -3) and (-7, -3)
Answer:
Mean = 78.2
Standard deviation = 5.8
Step-by-step explanation:
Mathematically z-score;
= (x-mean)/SD
From the question;
12% of test scores were above 85
Thus;
P( x > 85) = 12%
P(x > 85) = 0.12
Now let’s get the z-score that has a probability of 0.12
This can be obtained from the standard normal distribution table and it is = 1.175
Thus;
1.175 = (85 - mean)/SD
let’s call the mean a and the SD b
1.175 = (85-a)/b
1.175b = 85 - a
a = 85 - 1.175b ••••••••(i)
Secondly 8% of scores were below 70
Let’s find the z-score corresponding to this proportion;
We use the standard normal distribution table as usual;
P( x < 70) = 0.08
z-score = -1.405
Thus;
-1.405 =( 70-a)/b
-1.405b = 70-a
a = 70 + 1.405b ••••••(ii)
Equate the two a
70 + 1.405b = 85 - 1.175b
85 -70 = 1.405b + 1.175b
15 = 2.58b
b = 15/2.58
b = 5.81
a = 70 + 1.405b
a = 70 + 1.405(5.81)
a = 78.16
So mean = 78.2 and Standard deviation is 5.8
Answer:
Step-by-step explanation:
By definition:
The pre-meter P of a triangle ABC is equal to the sum of the length of its sides.
We know that:
The perimeter is:
Now we find the length of the sides:
Once the length of the sides is known, we use Heron's formula to calculate the area.
First I find the semiperimeter S.
Then the Area is:
Answer:
Part a) 
, 
Part b) 
Step-by-step explanation:
Let
x------> the number of ride tickets.
k-----> constant that represent the cost for festival admission
y----> the total cost
we know that
we have that
substitute the values
solve for k
The linear equation to calculate the cost for anyone who only pays for festival admission and rides is equal to
Answer:
5 people attended the fair.
Step-by-step explanation:
The parking tickets were 7 for the whole fam. You can subtract that off to get you $40. Each person cost $3+$5=$8. 40/8=5.
Hope this helps!
