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ECONOMICS. SS2. SCHEME OF WORK FOR FIRST TERM The concept of national income international trade and balance of payment. economic Integration. petroleum and the Nigerian economy. economic growth and economic development. Economics ss 2. Basic Tools For Economic Analysis.
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ECONOMICS SS2
SCHEME OF WORK FOR FIRST TERM • The concept of national income • international trade and balance of payment. • economic Integration. • petroleum and the Nigerian economy. • economic growth and economic development.
Economics ss 2 Basic Tools For Economic Analysis
Measure of variation (Dispersion) Measurement of dispersion is the degree to which numerical data spread around the average.
The most common measure of dispersion are: The range The mean deviation The standard deviation The variance
The Range • The range of a set of number is the difference between the highest and lowest number in a set. • Example : the range of the set 2,2,3,5,8,12,15 • Range =highest score- lowest score • 15-2=13
The Mean Deviation • This measures the dispersion around the arithmetic mean and is the sum of the arithmetic mean divided by the total numbers of times the value occur.
M.d= / N M.D = / f Where M.d= mean deviation = sigma or the sum of X = the variable X = the arithmetic mean N( f)= number eg times the value occurs
Example: • Find the mean deviation of the set of numbers 2,3,6,8,11 • Solution: • X= x • X = 2+3+6+8+11=30 = 6 5 5 N
/x-x/= 14 M.d= /x-x/ =14/5=2.5 N
Standard Deviation This is a measure of the degree of variation of a frequency distribution about its arithmetic mean. S.D = (X- X) 2 N
Example: 1 find the standard deviation of the following set of number 2,3,6,8,11 solution x = x = 2+ 3+ 6+8+11=30/5 N 5
2 s.d= (x-x) N
s.d= 54/5 = 10.8 s.d=3.29 s.d=3.3
The variance The variance of set of data is define as the square of the standard deviation . V= s.d 2
Assignment: calculate the standard deviation and variance of the following set of numbers 2,2,5,7,7,7,9,9,9,10,10,11,12,18.