Answer:
The required confidence inteval = 94.9%.
Step-by-step explanation:
Confidence interval: Mean ± Margin of error
Given: A confidence interval for the true mean diameter of all oak trees in the neighbourhood is calculated to be (36.191, 42.969).
i.e. Mean + Margin of error = 42.969 (i)
Mean - Margin of error = 36.191 (ii)
Adding (i) and (ii), we get

Margin of error = 42.969-39.58 [from (i)]
= 3.389
Margin of error = 
here n= 25 
i.e.

Using excel function 1-TDIST.2T(2.054,24)
The required confidence inteval = 94.9%.
Answer:
x ∈ [-2, 7]
Step-by-step explanation:
The given equation ...
x^2 -5x -4 ≤ 10
can be rewritten as ...
x^2 -5x -14 ≤ 0
and factored as ...
(x +2)(x -7) ≤ 0
Clearly, the "or equal to" condition will be met when x=-2 and x=7. For values of x between these numbers, one factor is negative and the other is positive. Hence the product will be negative. So, numbers in that interval are the solution set.
x ∈ [-2, 7]
Answer:
11
Step-by-step explanation:
9+9+11+15 = 44
44/4 = 11!
Answer:3 9/20
Step-by-step explanation:
Answer:
False
Step-by-step explanation:
False because you plug in 2 for d and makes the equation 81 + 2x2 > 90 then it`s just simple math 2x2 is 4 making it 81 + 4 > 90 and the answer is 85 > 90 which is false