Finite Math Examples
22 , 25 , 63 , 65
Step 1
Step 1.1
The mean of a set of numbers is the sum divided by the number of terms.
¯x=22+25+63+654
Step 1.2
Simplify the numerator.
Step 1.2.1
Add 22 and 25.
¯x=47+63+654
Step 1.2.2
Add 47 and 63.
¯x=110+654
Step 1.2.3
Add 110 and 65.
¯x=1754
¯x=1754
Step 1.3
Divide.
¯x=43.75
Step 1.4
The mean should be rounded to one more decimal place than the original data. If the original data were mixed, round to one decimal place more than the least precise.
¯x=43.8
¯x=43.8
Step 2
Step 2.1
Convert 22 to a decimal value.
22
Step 2.2
Convert 25 to a decimal value.
25
Step 2.3
Convert 63 to a decimal value.
63
Step 2.4
Convert 65 to a decimal value.
65
Step 2.5
The simplified values are 22,25,63,65.
22,25,63,65
22,25,63,65
Step 3
Set up the formula for sample standard deviation. The standard deviation of a set of values is a measure of the spread of its values.
s=n∑i=1√(xi−xavg)2n−1
Step 4
Set up the formula for standard deviation for this set of numbers.
s=√(22−43.8)2+(25−43.8)2+(63−43.8)2+(65−43.8)24−1
Step 5
Step 5.1
Subtract 43.8 from 22.
s=√(−21.8)2+(25−43.8)2+(63−43.8)2+(65−43.8)24−1
Step 5.2
Raise −21.8 to the power of 2.
s=√475.24+(25−43.8)2+(63−43.8)2+(65−43.8)24−1
Step 5.3
Subtract 43.8 from 25.
s=√475.24+(−18.8)2+(63−43.8)2+(65−43.8)24−1
Step 5.4
Raise −18.8 to the power of 2.
s=√475.24+353.44+(63−43.8)2+(65−43.8)24−1
Step 5.5
Subtract 43.8 from 63.
s=√475.24+353.44+19.22+(65−43.8)24−1
Step 5.6
Raise 19.2 to the power of 2.
s=√475.24+353.44+368.64+(65−43.8)24−1
Step 5.7
Subtract 43.8 from 65.
s=√475.24+353.44+368.64+21.224−1
Step 5.8
Raise 21.2 to the power of 2.
s=√475.24+353.44+368.64+449.444−1
Step 5.9
Add 475.24 and 353.44.
s=√828.68+368.64+449.444−1
Step 5.10
Add 828.68 and 368.64.
s=√1197.32+449.444−1
Step 5.11
Add 1197.32 and 449.44.
s=√1646.764−1
Step 5.12
Subtract 1 from 4.
s=√1646.763
Step 5.13
Divide 1646.76 by 3.
s=√548.92
s=√548.92
Step 6
The standard deviation should be rounded to one more decimal place than the original data. If the original data were mixed, round to one decimal place more than the least precise.
23.4