The mean ( average ) is given as 1200 hours.
The standard deviation is 200, sample size is 100.
Find the standard error:
√(200^2 / 100) = 20
Now calculate the confidence interval. For 95% the Z number is 1.96
Multiply Z by the standard error:
1.96 x 20 =39.2
Now find the range that the mean should be within:
1200 - 39.2 = 1160.8
1200 + 39.2 = 1239.2
The samples should be between 1160.8 and 1239.2 for a 95% confidence interval.
Since the average was 1050, which is below 1160.8 the bulbs are not in compliance.
First, the angles of triangle MNP add up to 180º. Since angle M is 142º and angle P is 24º, angle N must be (180-24-142)º or 14º.
Now angle N is congruent to angle U.
2x - 50 = 14
2x = 64
x = 32
Segment NP is congruent to segment US, so 13 = 2x - y AND x=32.
13 = 62 - y
y = 49
We have 55% and 80% antifreeze. We need 90 gallons of 75%.
F - 55% and E - 80%
A) F + E = 90
B) .55 F + .80 E = 67.50 (which is .75 * 90) Multiplying A) by -.55
A) -.55 F -.55 E = -49.50 (which is -.55 * 90) then adding A) & B)
.25 E = 18
E = 72 gallons of 80% and
F = 18 gallons of 55%
********* DOUBLE CHECK ******************
72 * .80 = 57.60 and 18 * .55 = 9.90
57.60 + 9.90 = 67.50 gallons of antifreeze and we have 90 total gallons
(67.50 / 90) * 100 = 75% correct!
Source: 1728.com/mixture.htm
Answer: 55 miles
Step-by-step explanation: Marcus goal is 80 miles for the week. he has already completed 25 miles of that goal so you would subtract 25 from 80 then you would find the miles still left
80-25=55