expected value variance help

Let X be a discrete random variable which can assume values x 1 , x 2 , x 3 ,x n with probabilities p 1 , p 2 , p 3 .. p n respectively then (a) Mean of X or expectation of X denoted by E(X) or m is given by (b) Variance of X denoted by s 2 is given ..

Sita has not finished her work yet. Seema has lived in Chennai since 2000. The servant did not respond when called. She cooked a meal for him yesterday. A moment ago I saw him in the office. I scolded Ram yesterday. Sarah went to the U.S. yesterday. The patient died before th..

If the degrees of freedom of the numerator is 15 and that of the denominator is 24 for testing the variances of two populations using F-test, then find the test value and the critical value at 95% confidence. The sample variances are 45 and 78. => 2.65, 1.83 ..

Find the F-test value for testing the difference between two population variances. The data shows the two samples from each of the populations. => 1.11 or 0.63 or 2.38 or 2.16..

Two thousand five hundred tickets are sold at $5 each for a prize worth $20,000. What is the expected value of the gain if a person purchases one ticket? => $7.998 or $3.00 or - $3.00 or $1.998..

expressed as number of children survived for every 100 births..

Which of the following is/are true? I. The mean value of F is approximately zero. II. F distribution is a family of curves based on the degrees of freedom of the variance of the numerator. III. F distribution is a family of curves based on the degrees of freedom of the vari..

The variance of the measures of rainfall in 20 different cities of two different states are 6 cm and 9.2 cm respectively. At a confidence level of 90%, find out the test value and check whether the variance of the rainfall in the first state is greater than that of the..

A researcher claims that the variance of the distances traveled by the buses of Indiana in a particular day is greater than that of the buses of Lowa. The journeys of 31 buses of Indiana and 25 for Lowa were observed and the variances were found as 5600 and 3200 respectively. Fi..

Do employees perform better at work with music playing? The average productivity level of 20 employees was 6.4 with a variance of 4 when the music was playing. Another day when the music was turned off, the productivity level was 5.2 with the variance of 2.8. Find the test ..