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Chapter 6: Q.1.1 (page 344)

North Carolina State University posts the grade distributions for its courses online.3Students in Statistics 101in a recent semester received 26%As, 42%Bs, 20%Cs, 10%Ds, and 2%Fs. Choose a Statistics 101student at random. The student鈥檚 grade on a four-point scale (with A=4) is a discrete random variable X with this probability distribution:

Say in words what the meaning ofP(X鈮�3) is. What is this probability?

Short Answer

Expert verified

P(X鈮�3)represents the probability that student will get a Bor more.

The required probability is 0.819.

Step by step solution

01

Given information 

Given in the question that, the North Carolina State University posts the grade distributions for its courses online.3 Students in Statistics 101 in a recent semester received 26%As, 42%Bs, 20%Cs, 10%Ds, and2%Fs. Choose a Statistics 101student at random. The student鈥檚 grade on a four-point scale (with A = 4) is a discrete random variable Xwith this probability distribution:

02

Explanation

The table is:

Value
0
1
2
3
4
Probability
0.011
0.032
?.362
0.457

To explain the term, the missing value is required to be computed. Let the missing value be x. The missing value can be calculated as:

localid="1649851625209" 0.011+0.032+x+0.362+0.457=1

x+0.862=1

x=0.138

P(X鈮�3)can be calculated as:

localid="1649918332279" P(X鈮�3)=P(X=3)+P(X=4)=0.362+0.457=0.819

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Most popular questions from this chapter

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