standard deviation formula

Find the standard deviation of the data set {2, 18, 4, 16}. => 5 or 5 2 or 3 2 or 4 2..

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. Find the standard error. => 1.15 or 0.8 or 8.0 or 1.0..

The average score on a Geography final examination was 70, with a standard deviation of 5. The average score on an English final examination was 85 with a standard deviation of 8. Which class was more variable? => English or cannot be determined or both are e..

Jessica scored 70 in an Algebra test that had a mean of 60 and a standard deviation of 8, and she scored 56 in French with a mean of 50 and a standard deviation of 5. Compare her relative positions in the two tests. => position in algebra is higher or positio..

A test on knowledge of word refinishing has a mean of 53 and a standard deviation of 6. Smithy has been taking this test for the past six months and her score has a mean of 71 with a standard deviation of 9. Compare the two variabilities. => The average score..

The standard deviation of the hemoglobin values (g/100ml) of 10 children is 1.7. Find the 99% confidence interval for the variance and standard deviation. Assume that the variable is normally distributed. => 1.26 < σ 2 < 14.75 ; 1.12 < σ ..

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 : The mea..

What percentage of area (approximately) under the normal distribution curve lies between a standard deviation of 1 and 2? => 15% or 13% or 27% or 30%..

30% of the people in a community went out on a vacation. If 600 people are selected at random, then find the standard deviation of the number of people who went out on vacation. => 126 or 180 or 11.23 or 13.4..

Find the lowest control limit for a normally distributed curve with a mean of 15 and a standard deviation of 2.5. => 12.5 or 10 or 7.5 or 22.5..