Answer:The diameter is 12cm
Step-by-step explanation:
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.
These 'l l' lines mean absolute value. essentially it's asking how many units away from 0 a number is. Because of this all absolute values are positive numbers
l-18l=18
Answer:
u spend half an hour on your blog
Step-by-step explanation:
(1/5)*(5/2) = 1/2
Answer:
Step-by-step explanation:
The directrix is a vertical line, so the parabola is horizontal. The focus lies to the left of the directrix, so the parabola opens to the left.
For a left-opening parabola:
x = a(y-k)²+h,
a < 0,
vertex (h,k)
focal length p = 1/|4a|
focus (h-p, k)
directrix: x=h+p
Apply your data
focus (1,-4)
directrix x=2
vertex (1.5,-4).
focal length p = 0.5
a = -1/|4p| = -½
x = -½(y-2)²+ ½