Normal Probability Distribution
Normal Probability Distribution: Overview
This topic covers concepts, such as, Probability Function, Continuous Random Variable, The Normal Approximation to Binomial Distribution & Continuity Correction etc.
Important Questions on Normal Probability Distribution
has Normal distribution with mean and standard deviation . Find the value of the variable such that the probability of the interval from the mean to that value is .

In a normal distribution, of the items are under and are over . Determine the mean and variance of the distribution.

In a normal distribution, of the items are under and are under . Determine the variance of the distribution.

Sketch the event if the length of a local bus journey from ranjith's home to school is a normally distributed random variable with mean minutes and standard deviation minutes.

Sketch the event if the length of a local bus journey from Raj' s home to school is a normally distributed random variable with mean minutes and standard deviation minutes.

A factory produces half-litre tins of oil. The volume of oil in a tin is normally distributed with mean and standard deviation . What percentage of the tins contain less than half a litre of oil? Use .

The mass of a newborn baby in a certain region is normally distributed with mean and variance . Estimate how many of the babies born last year had masses of less than . Use

For find the probability

For find the probability of

For find the probability of . Use

For find the probability of

The values in two datasets, whose probability distributions are both normal curves, are summarised by the following totals: On the same diagram, sketch a normal curve for each dataset.
and
and

. Use the normal approximation to find:

State the null and alternative hypotheses and test statistic for a test for the population mean for the random variable , sample value ; two-tailed test at level of significance.

Giving your answers to significant figures, evaluate:

Giving your answers to significant figures, evaluate:

Giving your answers to significant figures, evaluate:

If , find: upto four decimal places.

If , find:
(Correct the answer up to four decimal place)

Given that , state a suitable approximating distribution and use it to find:
