sample standard deviation formula

Select the incorrect statement(s). I. A sampling distribution of sample means is a distribution obtained by using the means computed from random samples of a specific size taken from a population. II. Sampling error is the difference between the sample..

Standard Deviation of a statistical data is defined as the positive square root of the arithmetic mean of the squared deviations of items from their arithmetic mean of the series under consideration. The standard deviation is denoted b..

of a statistical data is defined as the positive square root of the arithmetic mean of the squared deviations of items from their arithmetic mean of the series under consideration. The standard deviation is denoted by s (sigma). The standard deviatio..

The mean score on a standardized test is 100 with a standard deviation of 8. A random sample of 48 scores was found to have a mean of 98. State the null hypothesis and alternative hypothesis. => H o : The mean score = 100, H a : The mean score ≠ 100 or H o..

A sample of 30 RAM chips was tested for the average access time. The standard deviation was found to be 2 nanosec. Find the 90% confidence interval for the true standard deviation. Assume that the variable is normally distributed. => between 1.7 and..

A machine produces bolts, of which 10% are defective. Find the probability that in a random sample of 400 bolts produced by the machine, between 35 and 45 will be defective. Assume a standard deviation of 6. => 0.5640 or 0.6405 or 0.4605 or 0.4560..

If two samples have means of 24 and 28 and standard deviations of 4 and 6, with 12 and 15 as the sizes, find the z score for difference of two population means. => 2.07 or 7.73 or 1.07 or 1.93..

In a survey it was found that 20% of people living in a society watch channel A. If a random sample of 120 people is selected, then find the standard deviation of the number of people in the sample who watch channel A. => 24 or 19.2 or 4.38 or 96..

In a NBA playoff season the average number of points scored in a game was 200. Assume the standard deviation was 75. If a random sample of 20 games is selected, then what is the probability that the mean of the sample is lesser than 220? => 17.20% or 33.80% o..

Determination of sample size depends on: I. sample variance II. population standard deviation III. degree of confidence IV. maximum error of estimate => II and III only or all of the above or II, III and IV only or I, III and IV only..