sampling distribution problems

A random sample of 81 students was tested for the problem solving approach skills. The variance of the scores obtained from the sample was found to be 144. Find the 80% confidence interval for the variance and standard deviation. Assume that the variable is normally ..

What formula is used to gain information about a sample mean when the variable is normally distributed or when the sample size is 30 or more? => z = X - μ σ or z = X ‾ - μ σ n or z = X ‾ - μ σ n or z = X - μ σ..

Which of the following is a property of sampling distribution? I. Mean of sampling distribution equals population mean. II. Sample mean comes closer to population mean than any other unbiased mean. III. As sample size increases, variation ..

A population consists of the five numbers 2, 4, 6, 8 and 10. Consider all the samples of size 2 that can be drawn with replacement from the population. Find the mean of the sampling distribution means. Also find the difference between the population mean and mean of th..

The rms speed of an oxygen molecule in a sample at 300 K is about 480m/s. This does not mean that the speed of each molecule is 480 m/s. Many of the molecules have speed less than 480m/s and many have speed more than 480m/s. Maxwell derived an equation giving the distribution..

Random Variable and Probability Distribution - If is often very important to allocate a numerical value to an outcome of a random experiment. For example consider an experiment of tossing a coin twice and note the number of heads (x) obtained. Outcome : HH HT TH TT No. of heads (x) : 2 1 ..

It is often very important to allocate a numerical value to an outcome of a random experiment. For example, consider an experiment of tossing a coin twice and note the number of heads (x) obtained. Outcome HH HT TH TT No. of heads (x) 2 1 1 0 x is called a random variable, which can assume the valu..

Let S be a sample space associated with a given random experiment. A real valued function X which assigns to each w i S, a unique real number, X( w i ) = x i is called a random variable . Two types of random variables are 1. Continuous random variable, 2. discrete ra..

The rms speed of an oxygen molecule in a sample at 300 K is about 480m/s. This does not mean that the speed of each molecule is 480 m/s. Many of the molecules have speed less than 480m/s and many have speed more than 480m/s. Maxwell derived an equation giving the distribution o..

The basic assumption(s) for estimating the difference between two variances is/are: I. The samples must be dependent on each other. II. The samples must be independent of each other. III. The populations from which the samples were obtained must be normally distri..