Answer:

Step-by-step explanation:
<u>Confidence Interval</u>
When the population standard deviation
is known, the formula for a confidence interval for a population mean
is:

Where n is the sample size and z is the corresponding z-value from the standard normal distribution for the selected confidence level. The value of z for a 95% confidence interval is z=1.96. The rest of the values are

Calculating the confidence interval


Or, equivalently

Answer:
422.39 sq cm
Step-by-step explanation:
Find the area of the circle and subtract the area of the rectangle from it.
Circle area: pi*12^2, 144pi sq cm
REctangle area: 10*3=30sq cm
144pi-30≈422.39
Answer:
A: C = 15N
Step-by-step explanation:
30/2 = 15 (the cost of 1 class)
Answer: (-4, -2) and (6, -2)'s slope is 0, (2,9) and (2, -5)'s is undefined
Step-by-step explanation:
bro its not that hard, y1-y2 divided by x1-x2
X + 8x = 81
9x = 81, x = 9
y = 8(9), y = 72
Solution: (9, 72)