3/4. 4/8= 2/4. so 1/4+2/4=3/4
Answer: 37
Step-by-step explanation:
Given : Significance level : 
Critical value : 
margin of error : E= 1 mile per gallon
Population standard deviation:
miles per gallon.
We know that when the population standard deviation is known then the formula to find the sample size is given by :

[Round to the next whole number.]
Hence, the required number of automobiles should be used in the test = 37
She has $12,488 in savings
Step-by-step explanation:
Ariana plans to use $260 less than three-fourths of savings to buy a car.
If the purchase price of the car is 9,340, we need to find how much
she has in savings
To find the savings
- Assume that she has $x in savings
- Write an equation of x
- Solve the equation to find x
∵ She has $x in savings
∵ She plans to use $260 less than three-fourths of savings
- Three-fourths means
and less than means subtract
∴ She plans to use
x - 26
∵ The purchase price of the car is 9,340
- Equate the expression of x by 9,340
∴
x - 26 = 9,340
Now let us solve the equation
∵
x - 26 = 9,340
- Add 26 to both sides
∴
x = 9,366
- Divide both sides by
∴ x = $12,488
She has $12,488 in savings
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Answer: Margin of error = 6.58
Confidence interval = (26.91, 40.08)
Step-by-step explanation:
Since we have given that
Sample size n = 8
Sample mean = 33.5 minutes
Population standard deviation = 9.5 minutes
At 95% confidence interval,
α = 0.05
t = 1.96
So, Margin of error is given by

Confidence interval would be
Lower limit:

Upper limit:

Hence, the interval would be (26.91, 40.08)
But at standard deviation 7.2 minutes, the confidence interval was (27.5, 39.5)
Confidence interval using the standard normal distribution is wider than the confidence interval using t distribution.
Answer:
center of mass = ( 1 ,2 )
Step-by-step explanation:
attached below is the detailed solution of the problem
first we have to determine the value of m
M = ∫∫ dA
= 6
Mx = 12
attached solution below
My = 6
hence center of mass of a thin plate
x , y
= My/m , Mx/m
= 6/6 , 12/6
= ( 1, 2 )