Answer:
Step-by-step explanation:
<h3>Solution 1</h3>
The figure (kite) is symmetric and covers half of the area of rectangle with sides 8 units aby 10 units
<u>The area of the rectangle:</u>
<u>The area of the kite:</u>
- A = 1/2*80 = 40 sq. units
<h3>Solution 2</h3>
Split the kite into two triangles and calculate their area and add up
<u>Triangle DCB has b = 8, h = 2 and has area:</u>
- A = 1/2*8*2 = 8 sq. units
<u>Triangle DAB has b = 8, h = 8 and has area:</u>
- A = 1/2*8*8 = 32 sq. units
<u>Total area:</u>
Answer:
4 + (-5)
Step-by-step explanation:
4 - 5 = 4 + (-5) = -1
Additive inverse of 5 = (-5)
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
Mean or Average is all of the sums divided by how many of the choices are there, so all of 10,126+9,99+12,398+12,007+4567=49097 and divided by all the choices you have which is 5 is 9819.4
