standard deviation of the mean formula

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 greater than 700? => 2.28% or 2.82% or 47.72% or 47.27%..

The scores made by candidates in a certain test are normally distributed with mean of 500 and standard deviation of 100. What percentage of candidates received scores between 400 and 700? => 88.15% or 81.85% or 88.51% or 85.81%..

In an aptitude test conducted to qualify for a job, the scores given were normally distributed with a mean of 75 and a standard deviation 8. If only top 15% were to be selected, then find the cut - off scores. => 83.8 or 88.3 or 83.3 or 85..

Mean Deviation - The mean deviation of a statistical data is defined as the arithmetic mean of the numerical values of the deviations of items from some average value. Mean deviation is also known as average deviat..

Merits: 1. Mean deviation is easy to calculate. This measure is simple to understand. 2. This can be calculated from any average. 3. It is less affected by extreme observations. Demerits: 1. This is mathematically incomplete because it ign..

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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..

The number of ATM transactions of a bank per day were recorded at 12 locations in a city. The mean of the sample was 88.5 transactions, with a sample standard deviation of 42. Find the 98% confidence interval of the true mean. => 19.06 < μ < 157.94 o..

A soft drink company claims that the mean quantity of soft drink in a tin is 300 ml with a standard deviation of 5 ml. A random sample of 65 bottles from a shipment had a mean of 296.5 ml. Is the shipment is significantly different from the standard..