Light bulbs are measured in lumens (light output), watts (energy used), and hours (life).A Standard white light bulb has a mean life of 675 hours and a standard deviation of 50 hours.
A soft white light bulb has a mean life of 700 hours and a standard deviation of 35 hours.At
A local science competition, both light bulbs lasted 750 hours.Which light bulb's life span
Was better?
A)The standard white light bulb because it is 75 hours beyond the mean.
B)The soft white light bulb because it is 50 hours beyond the mean.
C)The standard white light bulb because it is 11% beyond the mean.
D)The soft white light bulb because it is 7% beyond the mean.
E)The standard light bulb because it lasted 1.5 standard deviations above the mean life.

Question

Quizplus · Accepted Answer

The performance of the light bulbs is better understood through standard deviations from the mean. The standard white light bulb lasted 750 - 675 = 75 hours beyond its mean, which is 75 / 50 = 1.5 standard deviations above the mean. The soft white light bulb lasted 750 - 700 = 50 hours beyond its mean, which is 50 / 35 ≈ 1.43 standard deviations above the mean. Therefore, relative to its distribution, the standard white light bulb performed better.

Light Bulbs Are Measured in Lumens (Light Output), Watts (Energy