Answer:
A)
Note that
Lower Bound = X - z(alpha/2) * s / sqrt(n)
Upper Bound = X + z(alpha/2) * s / sqrt(n)
where
alpha/2 = (1 - confidence level)/2 = 0.025
X = sample mean = 1723.4
z(alpha/2) = critical z for the confidence interval = 1.959963985
s = sample standard deviation = 89.55083319
n = sample size = 30
Thus,
Lower bound = 1691.355235
Upper bound = 1755.444765
Thus, the confidence interval is
( 1691.355235 , 1755.444765 ) [ANSWER]
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b)
We assumed taht the distirbution of these observations is approximately normally distributed.
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c)
Yes, because the values are not far away from each other.
Answer:
1.3 times 10 to the 25th power
Step-by-step explanation:
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the
10
. If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
It is 77.5. Using a calculator is more useful. ☺
Answer:
x = - 1, x = - 11
Step-by-step explanation:
Given
2| x + 6 | - 4 = 6 ( add 4 to both sides )
2|x + 6 | = 10 ( divide both sides by 2 )
| x + 6 | = 5
The absolute value function always gives a positive result, but the expression inside can be positive or negative, that is
x + 6 = 5 or - (x + 6) = 5
solve both
x + 6 = 5 ( subtract 6 from both sides )
x = - 1
or
- (x + 6) = 5 , that is
- x - 6 = 5 ( add 6 to both sides )
- x = 11 ( multiply both sides by - 1 )
x = - 11
