Binomial and normal distributions

Question 1 of 10

Marks are normally distributed with mean 60 and standard deviation 7. Find the mark that corresponds to z = 2.

Question 2 of 10

A fair-looking device succeeds with probability 0.2 each time. In 5 trials find P(exactly 2 successes) to 3 decimal places.

Question 3 of 10

The z-score is calculated as

Question 4 of 10

About what percentage of data lies within one standard deviation of the mean in a normal distribution?

Question 5 of 10

For X ~ B(5, 0.5), find the variance of X.

Question 6 of 10

A machine produces 5 per cent defective items. In a sample of 10, find the probability that none is defective and the expected number of defectives.

Question 7 of 10

A binomial experiment has

Question 8 of 10

A binomial distribution has independent trials.

Question 9 of 10

A negative z-score means the value is below the mean.

Question 10 of 10

For X ~ B(4, 0.5) the mean of X is ___