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.
Answer: D. (-5 < 5)
Step-by-step explanation:
-5 is NOT greater than its opposite (5)
Replace x any with their values:
3(-4) + 7(6) -12
Simplify:
-12 + 42 -12
Solve:
-12 + 42 -12 = 42
