A testing engineer in a light bulb factory is planning a study to estimate the average life of a large shipment of light bulbs. The engineer wants to estimate the average life within plus or minus 16 hours with 95 percent confidence. Assuming a process standard deviation of 90 hours, determine the sample size for this study.

a. 7
b. 43
c. 58
d. 122

d. 122

Step-by-step explanation:

Formula to find sample size : , where = prior population standard deviation, z= Critical z-value for confidence level and E = Margin of error.

As per given ,

Also , for 95% confidence level , z-value = 1.96

Now , Required sample size would be

Hence, the required sample size =122

Thus , the correct option is d. 122.

in the math equation 8 x 7 = 56, the 8 and the 7 are both factors of 56, since in this lesson we will use square tiles to figure out the factors of a whole find as many different arrays as you can, but follow one important rule: all the rows must have the i can make two rows of nine, so 2 and 9 are both factors of 18.

step-by-step explanation: