Answer:
x=−3x−7whatish(−4)
Step 1: Flip the equation.
28ah2istw−3x=x
Step 2: Add 3x to both sides.
28ah2istw−3x+3x=x+3x
28ah2istw=4x
Step 3: Divide both sides by 28h^2istw.
28ah2istw
28h2istw
=
4x
28h2istw
a=
x
7h2istw
Answer:
a=x7h2istw
3n+1 is the answer
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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
The answer is C. 8 units what you need to do is count how much from the starting point P is 4 units from A. simply double it by 2 to the new point to get 8 units.<span />
