Math I: Unit 2
Name: _________________________________________
STATISTICS INTRODUCTION
STATISTICS: practice of analyzing a set of data
Listing data values in ASCENDING Order: Smallest to Largest Value
Example#1: 3, 7, 5, 6, 6, 9, 4, 2, 1, 3
Ascending  1, 2, 3, 3, 4, 5, 6, 6, 7, 9
There are 10 Values
Example #2: -3.5, 7.2, 4.6, -1.2, 9.8, 2.9, -6.3, 8.4, 0.3
Ascending  -6.4, -3.5, -1.2, 0.3, 2.9, 4.6, 7.2, 8.4, 9.8
There are 9 Values
BASIC STATISTIC CALCULATIONS:
o MEAN: Arithmetic average of a data set
 Add all values in the data set and Divide by the number of values
Example#1:
Example#2:
1+2+3+3+4+5+6+6+7+9 = 45
-6.4-3.5-1.2+0.3+2.9+4.6+7.2+8.4+9.8 = 31.7
31.7
Mean 
 3.52
9
Mean 
45
 4.5
10
o MEDIAN: value that is found in the exact middle of the sorted data
 Data is in ascending order, count inward from the Largest and Smallest Number.
 If there is an ODD number of values, then innermost number from the data is the
median.
 If there is an EVEN number of values, then you must take the average of the two
innermost numbers from the data is the median.
Example#1:
Example#2:
1, 2, 3, 3, 4, 5, 6, 6, 7, 9
45
Median 
 4.5
2
-6.4, -3.5, -1.2, 0.3, 2.9, 4.6, 7.2, 8.4, 9.8
Median  2.9
o MODE: Most common number or repeated number in the data.
 If there is no repeated numbers, then NO mode.
 If different numbers are repeated the same amount of times, then there can be MORE
THAN ONE mode.
Example#1:
Example#2:
1, 2, 3, 3, 4, 5, 6, 6, 7, 9
-6.4, -3.5, -1.2, 0.3, 2.9, 4.6, 7.2, 8.4, 9.8
Mode  3,6
Mode  None
o RANGE: Difference of the MAXIMUM (largest) and MINIMUM (smallest) value.
Example#1:
Example#2:
1, 2, 3, 3, 4, 5, 6, 6, 7, 9
-6.4, -3.5, -1.2, 0.3, 2.9, 4.6, 7.2, 8.4, 9.8
Range  9.8  ( 6.4)  16.2
Range  9  1  8
EXAMPLES: For each list of data:
a. Write the data in ascending order.
b. Calculate the Mean, Median, Mode, Range of the data.
1)
10, 12, 18, 9, 5, 23, 19, 4, 9
Ascending Order: ______________________________________________________________
Mean: ____________________
Median: __________________
Mode: ____________________
Range: ____________________
2)
2.45, 3.72, 1.8, 2.6, 3.89, 4.23, 1.63, 2.97, 3.33
Ascending Order: _______________________________________________________________
Mean: ____________________
Median: __________________
Mode: ____________________
Range: ____________________
3)
65, 109, 47, 63, 27, 58, 47, 65, 93, 98, 87, 77
Ascending Order: _______________________________________________________________
Mean: ____________________
Median: __________________
Mode: ____________________
Range: ____________________
4)
– 3, 8, 14, – 7, 3, – 6, 11, 5, – 3, 2, – 6, 5, 5, 12, 19
Ascending Order: ______________________________________________________________
Mean: ____________________
Median: __________________
Mode: ____________________
Range: ____________________