The amount of time a certain brand of light bulb lasts is normally distributed with a

mean of 2000 hours and a standard deviation of 55 hours. What percentage light bulbs last less than 2080 hours, to the nearest tenth?

92.65 % light bulbs last less than 2080 hours

Step-by-step explanation:

We are given that The amount of time a certain brand of light bulb lasts is normally distributed

Mean =

Standard deviation =

We are supposed to find  What percentage light bulbs last less than 2080 hours, to the nearest tenth

Z=1.45

Refer the z table for p value

p value = 0.9265

Hence 92.65 % light bulbs last less than 2080 hours

i think it is 18

step-by-step explanation:

a=24; b=12

step-by-step explanation:

a/b=2: 1

a=2b

36/(1+2)=12

b=12

a=24