Me. a random sample of 16 light bulbs has a mean life of 650 hours and a standard deviation of 32 hours. assume the population has a normal distribution. construct a 95% confidence interval for the population mean.

Step-by-step

Mean = mu = 650

Standard deviation = sigma = 32

Sample size = 16

Therefore standard error of the given sample

standard error

=  standard deviation / sqrt(N)

= standard deviation /sqrt(16)

= 32/4

= 8

For 95% confidence interval, we need the normal curve to have an area of 0.95 between the limits, which, from normal distribution tables, the Z-value of 97.5% is 1.96, which means that for a 95% confidence interval, the values are between +/- 1.96 standard deviations, or +/- 1.96*8= +/- 15.68 hours.

Thus the confidence interval is

650 - 15.68 hours < X < 650+15.68 hours

634.32 < X < 665.68 hours

dhdhth

step-by-step explanation:

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b