In a binomial distribution, the probability of success is twice as that of failure. Then out of 4 trials, the probability of no success is ________.

If P(Z > z) = 0.5832 what is the value of z (z has a standard normal distribution)?

If P(Z > z) = 0.8508 what is the value of z (z has a standard normal distribution)?

If the area to the left of a value of z (z has a standard normal distribution) is 0.0793, what is the value of z?

Let z be a standard normal variable. If the area to the right of z is 0.8413, then the value of z must be: ________.

Monthly expenditure on their credit cards, by credit card holders from a certain bank, follows a normal distribution with a mean of  Rs. 1,295.00 and a standard deviation of Rs. 750.00. What proportion of credit card holders spend more than Rs. 1,500.00 on their credit cards per month?

The weights of newborn human babies are normally distributed with a mean of 3.2 kg and a standard deviation of 1.1 kg. What is the probability that a randomly selected newborn baby weighs less than 2.0 kg?

The time until first failure of a brand of inkjet printers is normally distributed with a mean of 1,500 hours and a standard deviation of 200 hours. What proportion of printers fails before 1000 hours?

Using the standard normal table, the sum of the probabilities to the right of z = 2.18 and to the left of z = -1.75 is ________.

Cape town is estimated to have 21% of homes whose owners subscribe to the satelite service, DSTV. If a random sample of your home in taken, what is the probability that all four home subscribe to DSTV?

A statistical analysis of long-distance telephone calls indicates that the length of these calls is normally distributed with a mean of 240 seconds and a standard deviation of 40 seconds. What proportion of calls lasts less than 180 seconds?

In a large statistics class the heights of the students are normally distributed with a mean of 172 cm and a variance of 25 cm. What proportion of students are between 165 cm and 181 cm in height?

The starting annual salaries of newly qualified chartered accountants (CA’s) in South Africa follow a normal distribution with a mean of  Rs.180,000 and a standard deviation of Rs. 10,000. What is the probability that a randomly selected newly qualified CA will earn between Rs. 165,000 and Rs. 175,000 per annum?

The random variable X is normally distributed with a mean of 70 and a standard deviation of 10. What is the probability that X is between 72 and 84?

Which of the following cannot generate a Poisson distribution?

Which of the following statements is/are true regarding the normal distribution curve?

Forty percent of the passengers who fly on a certain route do not check in any luggage. The planes on this route seat 15 passengers. For a full flight, what is the mean of the number of passengers who do not check in any luggage?

The average percentage of failure in a certain examination is 40. The probability that out of a group of 6 candidates atleast 4 passed in the examination are ________.

If for a binomial distribution b(n,p) mean = 4 and variance = 4/3, the probability, P(X ≥ 5) is equal to ________.

An experiment succeeds twice as often as it fails. The chance that in the next six trials, there shall be at least four successes is ________.

A manufacturer produces switches and experiences that 2 per cent switches are defective. The probability that in a box of 50 switches, there are atmost two defective is ________.

The parameters of the normal distribution \(f(x)=\left(\frac{1}{\sqrt{72 \pi}}\right)\)\(\frac{e^{-(x-10)^{2}}}{72}\) –∞ <  x  <  ∞ ________.

 In turning out certain toys in a manufacturing company, the average number of defectives is 1%. The probability that the sample of 100 toys there will be 3 defectives is ________.

In a parametric distribution the mean is equal to variance is ________.

If X ~ N(μ, σ²), the maximum probability at the point of inflexion of normal distribution is ________.

If Z is a standard normal variate, the proportion of items lying between Z = –0.5 and Z = –3.0 is ________.

If X ~ N(9,81) the standard normal variate Z will be ________.

Normal distribution was invented by ________.