Answer:
E(T) = 200.57
SD(T) = 0.4625
Step-by-step explanation:
a) Given:
Mean:
Backstroke = 50.72
Breaststroke = 55.51
Butterfly = 49.43
Freestyle = 44.91
To find the mean E(T), let's sum up all values of mean.
E(T) = 50.75 + 55.31 + 49.43 + 44.91
E(T) = 200.57
b) Given:
Standard deviation :
Backstroke = 0.22
Breaststroke = 0.16
Butterfly = 0.3
Freestyle = 0.24
To get the SD(T), let's first find their variance.
Variance = SD²
Therefore,
Vbackstroke = 0.22² = 0.0484
Vbreatstroke= 0.16² = 0.0256
Vbutterfly = 0.3² = 0.09
Vfreestyle = 0.24² = 0.0576
[tex] SD(T) = \sqrt{0.0484 + 0.0256 + 0.09 + 0.0576} [/tex]
SD(T) = 0.4625