standard deviation versus standard error of the mean

The distances traveled in kilometers by a person on four different days is: 63, 42, 55, 40. Find the mean distance and standard deviation. => Mean = 54, standard deviation = 9.5 or Mean = 54, standard deviation..

Let X denote the number of scores on a test. If X is normally distributed with a mean of 90 and a standard deviation of 10, find the probability that X is not less than 70. => 0.4772 or 0.7472 or 0.7972 or 0.9772..

The scores made by candidates in a certain test are normally distributed with mean 500 and standard deviation 100. What is the percentage of candidates who scored less than 400? => 15.87% or 17.85% or 18.57% or 15.78%..

The scores made by candidates in a certain test are normally distributed with mean 500 and standard deviation 100. What percentage of candidates received scores which differ from 500 by more than 150 points? => 43.23% or 13.36% or 43.32% or 6.68%..

The number of stamps of different countries collected by Edward are 96, 98, 98, 105, 36, 87, 95 and 93. Find the mean and the standard deviation. => 416.25, 20.4 or 88.5, 20.4 or 20.4, 5.77 or 20.4, 4.51..

As the sample size n increases without limit, the shape of the distribution of the sample means taken with replacement from a population with mean μ and standard deviation σ will approach a normal distribution. This distribution will have mean..

The mean number of males and females in 40 classrooms of a school are 25 and 22 with the standard deviations 12.2 and 15.6 respectively. Do the mean values differ at 98% and 95% confidence levels? => do not differ at 95% and also at 98% or do not differ at 98..

A sample of scores of 250 candidates has a mean of 47.2 with a standard deviation of 18.6. Find 90% and 95% confidence interval of the population mean and determine which is larger? => (45.3, 49.1) and (44.9, 49.5) and 95% or (45.26, 49.14) and (44.89, 49.51)..

Which of the following controls the spread of normal curve? I. standard deviation II. mean III. median IV. mode => III and IV only or II only or III only or I only..

The 95% confidence interval for the mean number of tablets in a bottle of calcium tablets is between 149.04 and 150.96. The standard deviation is 3 tablets. Find the size of the random sample that was used to determine this interval. => 40 or 38 or 6 or 150..