Answer:
The margin of error for a 90% confidence interval is 16.4
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 25
Standard deviation = 50
Margin of error =
Putting the values, we get,
Thus, the margin of error for a 90% confidence interval is 16.4
0=40-10t-5t^2
t^2+2t-8=0
(t+4)(t-2)=0
t=-4 (not a solution) or t=2
Answer: after 2 seconds
The number that twice the sum of it and negative seven is eight is 11.
<h3>How to find the number ?</h3>
Twice the sum of the number and negative seven is eight. The number can be found as follows:
let
the number = x
According to the word expression, twice the value of the addition of x and minus seven is equals to 8. Hence, we will find the value of x in the equation formed from the words expression.
The variable x is the required number.
Therefore,
2(x + (-7)) = 8
2(x - 7) = 8
open the brackets
2(x - 7) = 8
2x - 14 = 8
add 14 to both sides of the equation
2x - 14 = 8
2x - 14 + 14 = 8 + 14
2x = 22
divide both sides by 2
x = 22 / 2
x = 11
learn more on numbers here: brainly.com/question/11234992
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Answer:
C
Step-by-step explanation:
Answer:
Their present age are 15 and 18
Step-by-step explanation:
a : b = 5 : 6
