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
4 500-60 = 4 440
4 440/38 = 116.8
At most they would be able to invite 116 people to the reception with their budget.
(1,3) and (7,3) falls on the same horizontal line. hence, the distance is just equal to 6 units. (7,3) and (7,7) meanwhile lie on the same vertical line. hence the distance is 4. (7,7) and (4,7) lie on the same horizontal line with a distance of 3.
Finally, to get back to point (1,3) - (4,7) ----> (1,3), 3 to the left and 4 down, the diagonal being 5.
6+4+3+5= 10 + 8 = 18.
Answer:geometric
Step-by-step explanation: purrrr
The equation you can use to relate L to D uses the information in the first part of the problem. First, if we just add 4 miles every day (ignoring the other piece), the length of the road would be 4 times the number of days, or L = 4D. But since we started with 57 miles built, we have to add that in order to get the total length, so the equation would be:
L = 4D + 57
You can use this question to find any value of L or D if you know one of them. According to the questoin, we know the crew worked 34 days (or D). So if you plug in 34 for D you'll get:
L = 4(34) + 57 ->
L = 136 + 57 ->
L = 193
