z score

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..

Find the z scores of three students who had a score of 93, 80, 84 in an examination for a pre-medicine course which has a mean of 84 and a standard deviation of 4. => 9, - 4, 0 or 23.25, 20, 21 or 2.25, - 1, 0 or - 2.25, 1, 0..

Which of the following statement(s) is/are true? I. If a student secured 75th percentile in an exam, then it means that he scored 75 out of 100. II. A statistic that tells the number of standard deviations a data value is above or below the mean is called z score. III...

Select the true statement(s). I. The measure of central tendency used in exploratory data analysis is mean. II. The measure of central tendency used in z score is median. III. The mean and standard deviation is better than five-number summary for describing a skewed distribution..

The number of candles placed on two tables A and B at 25 instants of time is shown. Give the z score value and verify if the mean number of candles placed on both the tables differ at 98% confidence level. => 0.2092, do not differ or - 0.551, do not differ or 0.9, do not differ ..

The mean weight of 30 students of a class is 52 and that of 40 students of another class is 50. If the standard deviations are 3 and 4.2, then find the z score value and verify if the mean weight of students of first class is greater than that of the second class at 90% confiden..

The mean costs of two sets of soaps of same weight are $4.30 and $4. If the sets were 40 and 30 units in size with the standard deviations $0.60 and $0.90, then find the z score value and verify if they differ in their mean cost at 95% confidence level. => 1.58, mean costs of bo..

A person verified the records of past 20 years of one estate and that of past 18 years of another estate. The average number of families leaving in the first estate was found as 23 and that of second estate as 20. If the standard deviations were 6 and 8, find the z score value a..

If the average number of people having high cholesterol levels in 20 cities of a state is 370 and that of 25 cities of another state is 350, then find the z score value and verify if there is any difference in both the means at 90% confidence with the variances 120 and 163. => 5..

What is the formula to find the z score for the difference between two population means, if X 1 and X 2 are the sample means, s 1 2 and s 2 2 are the sample variances and n 1 and n 2 are the size of the samples? (Assume both n 1 and n 2 are greater than..