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
You go down to the negative number x is first and then you go to the positive number which is y
Answer:
59/1
Step-by-step explanation:
0 = 0 = 0 = 0 = 0 < 54 < 56 < 59
0 is equal to 0 is equal to 0 is equal to 0 is equal to 0 is less than 54 is less than 56 is less than 59
Answer:
<em>The measure of angle J is 44°</em>
Step-by-step explanation:
<u>Isosceles Trapezoid</u>
The isosceles trapezoid has its non-parallel sides of the same length, thus the angles they form with their respective parallel sides are congruent.
It means: Angle J is congruent with angle K and angle M is congruent with angle L
The sum of angles in a trapezoid is 180*(4-2)=360°
Thus:
Joining like terms:
Adding 24:
Dividing by 64:
x=6°
Thus:
The measure of angle J is 44°
