Scores on a certain test follow the normal curve with an average of 1350 and a standard deviation of 120. What percentage of test takers score below 1230? (Use the empirical rule.) 16%, 1230 is one ...

This article examines the accuracy of normal approximations to confidence limits for the binomial (n,p) parameter p. The method of getting "exact" values from an F table is too slow for practical use ...

A recent comparative analysis of alternative interval estimation approaches and procedures has shown that confidence intervals (CIs) for true raw scores determined with the Score method—which uses the ...

The normal distribution is a continuous probability distribution that is symmetrical, bell-shaped, and centred around its mean. It is one of the most important distributions in statistics because many ...

Use the sliders to change the number of trials (n) and the probability of success (p). Use the checkboxes to see the normal approximation to the binomial distribution and to compute cumulative ...

Clustered data frequently occur in biomedical research fields and clinical trials. The log-rank tests are widely used for two-independent samples of clustered data tests. The randomized block design ...