statistics

STATISTICS STUDIES

What are the odds of you guys requesting statistics as a study topic? 1 out of 2.

Statistics as a field of study is hugely challenging. Not only are you needing to learn how to gather data, but you’re having to cover other topics that range from mathematics to sociology, economics or accounting and finance; and different universities will have different approaches to teaching key skills and the fundamentals behind them, not to mention the different fields of specialisation. So without any further delay, here are our top tips for studying statistics.

1. Have Clear Goals When Tackling Statistics

Like any topic of study, it’s good to have a plan in place for what you wish to achieve with your study time. Outline the goals of your study sessions and allocate mile-stones for self-checking to keep yourself on track.

2. Spread Your Study Over a Set Period of Time

Statistics require time to take in, comprehend and commit. Set aside an hour to two hours per day over a 5 – 6 day period, and remember to take a 10 minute break every hour. Cramming will result in your forgetting more than you have taken in.

3. Study the CONCEPT, not the Formula

According to Gary Ramseyer of Illinois State University, a good instructor will never ask you to memorise formula. It’s more beneficial to study the concept behind statistical techniques. Not only will the concept stay with you longer, you can always look for formula up in a textbook or online in the real world.
EG: Here’s a list of statistical formulae from the good people of www.statisticssolutions.com
https://www.statisticssolutions.com/common-statistical-formulas/

4. Understand the Basics of Statistics

4.1 Mean and Median

Mean and Median are the foundation to other, more complicated concepts.
Mean: Is the average of a set of numbers.
• To calculate the mean, add all of the numbers in your data set and divide the sum by the number of numbers in the set. For example, if your data set includes the numbers 2, 4, 6, 8, 10, and 12, the sum of the set is 42. 42 divided by 6 (the number of data points) is 7. 7 is your mean.

Median: Is the Middle of a set of numbers.
• The median is the just the middle of any set of numbers. So the median of the data set 2, 4, 6, 8, and 10 is 6. If you have an even number of data points, add the 2 middle numbers of divide by 2.

4.2 Variance and Mean

Variance: The average of squared differences from the mean. This will help you understand how spread out a set of data is.

• For example, let’s say you and your 3 friends each have a dog, and their heights are 12 in (30 cm), 20 in (51 cm), 16 in (41 cm), and 32 in (81 cm). First, take the mean of their heights by adding all 4 heights together and dividing by 4. In inches, this would be 12 + 20 + 16 + 32, which equals 80. Divide that by 4 (the total number of dogs) to get 20. So the mean of their heights is 20 in (51 cm).
• Then calculate the variance by subtracting each individual height from the mean and squaring it. So 20 – 12 is 8, and 8 squared is 64. 20 – 20 is 0, and 0 squared is still 0. 20 – 16 is 4, and 4 squared is 16. And 20 minus 32 is -12, and -12 squared is 144. 8 + 0 + 16 + 144 = 168.
• To get the final variance, divide the sum of the squared differences from the mean (168) by the number of dogs (4). So the variance of this data set is 42.

4.3 Variance and Deviation

Standard deviation tells you how much each data point differs from the mean.
You need to have your variance first, then you take the square root of the variance. If the number includes a decimal, round it to the nearest whole number.

• For example, if the variance of your and your friends’ dogs’ heights is 42, the standard deviation is the square root of 6.48. You’d round that down to 6. That tells you that, on average, each dog is about 6 in (15 cm) away from the mean of the dogs’ heights.

4.4 Normal Distribution

Normal Distribution: Is a graphic distribution of a set of data’s mean and the variations from the mean. You will need to learn how to calculate z values (the points on the graph).

The basic z score formula for a sample is:
z = (x – μ) / σ
For example, let’s say you have a test score of 190. The test has a mean (μ) of 150 and a standard deviation (σ) of 25. Assuming a normal distribution, your z score would be:
z = (x – μ) / σ
= 190 – 150 / 25 = 1.6.
The z score tells you how many standard deviations from the mean your score is. In this example, your score is 1.6 standard deviations above the mean.

5. Practice Makes Perfect Statistics

The more you practice and the more varied the problems you tackle, the better. Statistics is an applied science, having the theory to back you is great, but until you understand the maths behind them and understanding means doing. If you reach a part of your study materials that discusses a new formula or concept, take the time to work them out by yourself before moving on.

Other simple tips are to take clear notes and to always ask your lecturer questions if you don’t understand a concept. By following these tips, and knowing the basics you’re giving yourself the advantage for studying your statistics.

Sources:
We would like to thank the following websites for their tips, tricks and articles:

https://www.wikihow.com/Study-Statistics
http://www.howtostudy.org/statsguide.php
Topuniversities.com

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