We are given the following data:
Sample Size = n = 1000
Sample Mean = u = 15 hours
Population Standard Deviation = s = 2 hours
Since we know the population standard deviation, we can use z distribution to find the confidence interval about the mean. z value for 95% confidence interval is 1.96.
Formula for the confidence interval is:
Using the values in the formula, we get:
Therefore, the 95% confidence interval about the population mean is 14.88 hours to 15.12 hours. So B option is the correct answer.
Answer:
Step-by-step explanation:
We are given the trigonometric equation of:
Let u = 4x then:
Find a measurement that makes sin(u) = √3/2 true within [0, π) which are u = 60° (π/3) and u = 120° (2π/3).
Convert u-term back to 4x:
Divide both sides by 4:
The interval is given to be 0 ≤ 4x < π therefore the new interval is 0 ≤ x < π/4 and these solutions are valid since they are still in the interval.
Therefore:
Answer:
y = 5
x = 10
Step-by-step explanation:
-4(2y) + 11y
-8y + 11y = 15
3y = 15
/ 3 /3
y = 5
x = 10
9514 1404 393
Answer:
27
Step-by-step explanation:
You want to find x when c = 120.
120 = x^2 -24x +39
x^2 -24x -81 = 0 . . . . . . subtract 120 to put in standard form
(x -27)(x +3) = 0 . . . . . .factor it
Solutions are ...
x = 27, x = -3 . . . . . values of x that make the factors zero
The number of flags manufactured for a cost of $120 is 27 flags.
