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Use the following information to answer the next seven exercises: A ballet instructor is interested in knowing what percent of each year's class will continue on to the next, so that she can plan what classes to offer. Over the years, she has established the following probability distribution.

- Let X=the number of years a student will study ballet with the teacher.

- Let localid="1649790047208" P(x)=the probability that a student will study ballet xyears.

What does the column"x×P(x)"sum to and why?

Short Answer

Expert verified

Sum of xP(x)is 4.5and it is mean of variableX.

Step by step solution

01

Table for probability of students

02

Calculation for sum

For sum of xP(x):

From table,

localid="1649790200294" x1P(x1)=0.1,x2P(x2)=0.1,x4P(x4)=0.6

x3P(x3)=0.3,x5P(x5)=1.5

x6P(x6)=1.2,x7P(x7)=0.7

So,

xP(x)=xii=17P(xi)

=0.1+0.1+0.3+0.6+1.5+1.2+0.7

=4.5

=4.5

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