In: Statistics and Probability
. Choose a data set with 10-30 data values. (This could include but Is not limited to the closing price of a stock for 10-20 days, 10-20 of your exam grades, etc) You must all choose a different data set!! Compute the mean, median, mode, quartiles, IQR, SIQR, variance and standard deviation. Then report the relative position (from the median in terms of amount of SIQRs and also from the mean in terms of amount of standard dev's) of both the highest and lowest data values.
We take number of COVID-19 cases in different countries (as reported on 3:00 AM GMT, 20-04-2020) as follows.
Country | No of cases | Country | No of cases | Country | No of cases |
USA | 764265 | China | 82747 | Switzerland | 27740 |
Spain | 198674 | Iran | 82211 | Portugal | 20206 |
Italy | 178972 | Russia | 42853 | India | 17615 |
France | 152894 | Brazil | 38496 | Peru | 15628 |
Germany | 145742 | Belgium | 38496 | Ireland | 15251 |
UK | 120067 | Canada | 35056 | Austria | 14749 |
Turkey | 86306 | Netherlands | 32655 | Sweden | 14385 |
Suppose, random variable X denotes the number of COVID-19 cases in different countries.
In our data, number of countries observed
Mean-
Mean is given by
Median-
Arranging the given data in increasing order we get as follows.
14385, 14749, 15251, 15628, 17615, 20206, 27740,
32655, 35056, 38496, 38496, 42853, 82211, 82747,
86306, 120067, 145742, 152894, 178972, 198674, 764265.
There are 21 values.
So, median is (21+1)/2 th i.e. 11 th value.
Hence, median is 38496.
Mode-
We observe that 38496 occurs for highest (twice) number of times.
Hence, mode is 38496.
Quartiles-
Second quartile (also known as median) is the (21+1)/2 th i.e. 6 th value.
Hence, second quartile is 38496.
This data separates the whole data set into two equal parts.
First quartile is the (11+1)/2 th i.e. 6 th value.
Hence, first quartile is 20206.
Third quartile is the (11-1)+(11+1)/2 th i.e. 16 th value.
Hence, third quartile is 120067.
IQR-
Inter quartile range = 120067 - 20206 = 99861
SIQR-
Semi-inter quartile range = (120067 - 20206) / 2 = 49930.5
Variance-
Variance is given by
Standard deviation-
Standard deviation is given by
Relative position-
Highest - Median = 764265 - 38496 = 725769 = 14.53558 * SIQR
Median - Lowest = 38496 - 14385 = 24111 = 0.4828912 * SIQR
Highest - Mean = 764265 - 101190.9 = 663074.1 = 13.27994 * SIQR
Mean - Lowest = 101190.9 - 14385 = 86805.9 = 1.738535 * SIQR