Christian received a promotion at work . His hourly salary increased from 12 to 18 . What percent did his hourly wage increase
2 answers:
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Answer:
See explanation.
Step-by-step explanation:
Let BC be the diameter of the circle with center at point O, AB be the chord and ∠ABC=30°. OD is the distance from the center to the chord.
Consider triangle BDO. This triangle is special 30°-60°-90° right triangle. The leg OD is opposite to the angle of 30° and is half of the hypotenuse. The hypotenuse of the triangle BDO is BO. BO is the radius of the circle and is equal to half of the diameter AB. Thus,
Answer:
The 95% confidence interval estimate for the population mean life of compact fluorescent light bulbs in this shipment is between 7,255 hours and 7,745 hours.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 7500 - 245 = 7255 hours.
The upper end of the interval is the sample mean added to M. So it is 7500 + 245 = 7745 hours.
The 95% confidence interval estimate for the population mean life of compact fluorescent light bulbs in this shipment is between 7,255 hours and 7,745 hours.