Acompany has developed a new type of light bulb, and wants to estimate its mean lifetime. a simple random sample of 12 bulbs had a sample mean lifetime of 673 hours with a sample standard deviation of 75 hours. it is reasonable to believe that the population is approximately normal. find the lower bound of the 95% confidence interval for the population mean lifetime of all bulbs manufactured by this new process.

625.35

Step-by-step explanation:

Given : Sample size : n= 12, which is less than 30 , so we use t-test.

Sample mean :

Standard deviation :

Significance level :

Critical value :

The confidence interval for population mean is given by :-

Hence, the  lower bound of the 95% confidence interval for the population mean lifetime of all bulbs manufactured by this new process = 625.35

squares, rhombus, rectangles

yes

step-by-step explanation:

yes