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
Hello!
Answer:
x=7(a+y)
Step-by-step explanation:
Hope this helps!
Answer:
I got 6 and 28/99
Step-by-step explanation:
I put it in a calculator about 10 times and this was the answer every time, sorry if it wasn't helpful
Answer:
Working memory
Step-by-step explanation:
Working memory is a system the brain uses for temporarily storing and managing the information required to carry out complex cognitive tasks. The central executive part of the prefrontal cortex at the front of the brain is responsible for working memory. It serves as a temporary store for short-term memory, where information is kept available while it is needed for current reasoning processes.
So to be successful in holding the number 2.82 in my head while sorting, one must keep the information maintained in short-term storage by using one's working memory.
answer
<span>A.4 2/3 is greater than 4.63
because 4 2/3 = 4.67</span>
