Essential Formulas To Solve Any Stats Homework Quickly

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The key to solving any statistics problem quickly depends on how much familiar you are with the major Statistical analysis methods and their working formulas. Time is always of the essence; getting a Statistics homework done with quick precision gives you an edge during your examinations as well.

This write-up offers a brief lesson on all the major analytical technique, their working formulas and even some short cut tips. Read on to get your stat problems done without breaking a sweat.

Mean and Median

The most common descriptive statistical techniques used to measure central tendency in a data population are mean and median.

Say, there is a population of five children with a weight distribution of

100 pounds

100 pounds

126 pounds

140 pounds

129 pounds

Then the median is the value that lies at the midpoint of this distribution, that is, median= 126 pounds. Note that this is only applicable for odd valued distributions. For even valued ones, the average of the two middle values is taken as the median. In every case, samples should be arranged in ascending order.

The mean value is the average of the whole distribution, given by the working formula = ∑ (weight samples)/number of samples. The mean value of this example distribution is, therefore 119 pounds.

Variability

Your homework question may ask you to find the variance or deviation of the data from the mean value. Variance and standard deviation are the major techniques to measure variability.
The interquartile range is another method that describes variability in a data set that has been divided into quartiles.

The variance of a population is given as the average squared deviation from the mean of a distribution. The working formula is given by σi2 = ∑(Xi - µ)2 / N,

where σ is the variance of the ‘ith’ value, Xi is the value, µ is the mean and N is the total numbers of the population.

For a particular population, the standard deviation is the square root of variance. The formula to obtain it is σ=sqrt[σ2] .

Interquartile range measures variability by dividing rank-ordered data set into four equal parts. Q1, Q2, Q3 and Q4 are the value that divides the data.

Q1 is the midpoint value of the first half.

Q2 is the median value of the set.

Q3 is the midpoint value of the second half.

Inter-quartile range is then given by IQR=Q3-Q1.

So, these important statistical formulas will no doubt come in handy during your homework. Keep them in mind if you want those high grades for yourself.