Answer: The 95% confidence interval is approximately (55.57, 58.43)
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Explanation:
At 95% confidence, the z critical value is about z = 1.960 which you find using a table or a calculator.
The sample size is n = 17
The sample mean is xbar = 57
The population standard deviation is sigma = 3
The lower bound of the confidence interval is
L = xbar - z*sigma/sqrt(n)
L = 57 - 1.960*3/sqrt(17)
L = 55.5738905247863
L = 55.57
The upper bound is
U = xbar + z*sigma/sqrt(n)
U = 57 + 1.960*3/sqrt(17)
U = 58.4261094752137
U = 58.43
Therefore the confidence interval (L, U) turns into (55.57, 58.43) which is approximate.
Answer: x=4
Step-by-step explanation:
-8-x=x-4x
-8-x=-3x
-8=-2x
x=4
Answer:
The cost of each cotton candy bag is $4.
Step-by-step explanation:
Consider the provided information.
Let, the vendor has 
dollar at the starting of each day.
Let, the cost of each cotton candy bag is 
.
Now when she sells a total of 12 bags, she has $128.
.....(1)
After she sells a total of 20 bags, she has $160.
....(2)
Subtract equation 1 from equation 2.
Hence, the cost of each cotton candy bag is $4.
Answer:
B
Step-by-step explanation:
For each equation, set x to 0. A is correct because if x=o, then y will equal 38.910.
arcsin(1/2) means "the angle whose sine is 1/2".
That's 30° .
y = cos(30°) = (1/2)√3 = about 0.866 .
