Z-transform

Z transforms of unit step function is

• 1

• 0

Which of the following is damping rule?

A random Sample of 50 items gives the gives the mean 6.2 and variance 10.24 . can it be regarded as drawn from a normal population with mean 5.4 at 5% level of Significance?

• NH Accepted ,the sample is drawn from the population with mean 5.4

• AH Accepted ,the sample is drawn from the population with mean 5.4

• NH Accepted ,the sample is drawn from the population with mean 6.2

• AH Accepted ,the sample is drawn from the population with mean 6.2

Sample size n is taken to be small if

We use the 't' variable when

• The 'z' variable cannot be found

• When the number of samples is small

• When the number of samples is large

• When we know the value of the population mean

The mean height of random Sample of 100 individuals from a polpulation is 160 . the S.D. of the sample is 10.would it be reasonable to suppose that the mean height of the population is 165 ?