Respuesta :
Answer:
The mean number of students in a Statistics class = 25.47
The standard deviation of the number of students in a Statistics class = 1.081.
Step-by-step explanation:
We are given the following probability distribution for the number of students in statistics classes below;
X P(X) [tex]X \times P(X)[/tex] [tex]X^{2} \times P(X)[/tex]
23 0.08 1.84 42.32
24 0.12 2.88 69.12
25 0.15 3.75 93.75
26 0.55 14.3 371.8
27 0.10 2.7 72.9
Total 1 25.47 649.89
The missing value against value 26 is calculated as;
= 1 - (0.08 + 0.12 + 0.15 + 0.10) = 0.55
The mean of the following data is given by;
Mean,[tex]\mu[/tex] = [tex]\sum X \times P(X)[/tex] = 25.47
The variance of the following data is given by;
Variance,[tex]\sigma^{2}[/tex] = [tex]\sum X^{2} \times P(X) - (\sum X \times P(X))^{2}[/tex]
= [tex]649.89 - (25.47)^{2}[/tex]
= 1.1691
Standard deviation = [tex]\sqrt{1.1691}[/tex] = 1.081
