Answer:
-7
Step-by-step explanation:
To find y, follow these steps:
4y - 2 (1 - y) = -44
First, distribute the -2 into the parenthesis:
4y - 2 + 2y = -44
The reason the 2y is positive is due to the fact that negative and negative cancel each other out and form a positive.
Now, combine like terms:
6y - 2 = -44
To get y, you need to isolate it from the constants. In order to do so, do the inverse relationship for the constant -2. To do this, add 2 to -44:
6y = -42
Now, divide six on both sides. You divide because six is currently being multiplied with y. Keep in mind that the 42 is still negative!
y = -7
Hope this helps!
Let's call our estimate x. It will be the average of n IQ scores. Our average won't usually exactly equal the mean 97. But if we repeated averages over different sets of tests, the mean of our estimate the average would be the same as the mean of a single test,
μ = 97
Variances add, so the standard deviations add in quadrature, like the Pythagorean Theorem in n dimensions. This means the standard deviation of the average x is
σ = 17/√n
We want to be 95% certain
97 - 5 ≤ x ≤ 97 + 5
By the 68-95-99.7 rule, 95% certain means within two standard deviations. That means we're 95% sure that
μ - 2σ ≤ x ≤ μ + 2σ
Comparing to what we want, that's means we have to solve
2σ = 5
2 (17/√n) = 5
√n = 2 (17/5)
n = (34/5)² = 46.24
We better round up.
Answer: We need a sample size of 47 to be 95% certain of being within 5 points of the mean
Answer:
Interest earned at 3.9 percent rate is $31.2
Interest earned at 2 percent rate is $5.8
Step-by-step explanation:
A = P(1 + rt)
Where 'A' is the amount, 'r' is the rate and 't' is the time in years
When;
P = $1200
r = 3.9%
t = 
years
Then,
A = $1200(1 + 0.039())
A = $1200 + $31.2 = $1231.2
Interest = Amount - Principal
Interest earned at 3.9 percent rate is $1231.2 - $1200 = $31.2
When;
P = $580
r = 2%
t = 
years
Then,
A = $580(1 + 0.02())
A = $580 + $5.8 = $585.8
Interest earned = Amount - Principal
Interest earned at 2 percent rate = $585.8 - $580 = $5.8
Answer:
x = 52°
Step-by-step explanation:
I have attached an image to depict the given angles.
From the attached image, we can see that the unknown angle is x°.
Thus, since that corner is 90°, then;
x + 38 = 90
Subtract 38 from both sides to get;
x = 90 - 38
x = 52°
