I need help on coding for R program using RStudio. Please help me with these que

Question

I need help on coding for R program using RStudio. Please help me with these questions!

In a multiple choice quiz, there are 10 questions and 4 choices for each question (a, b, c, d). One student has not studied for the quiz at all, and decides to randomly guess the answers. Denote X the number of questions he gets right. 1. What is the probability distribution for X? Specify the parameters of that distribution. 2. What is the probability that he gets less than 5 questions right? (Hint: use pbinom or dbinom function) 3. Compute P(s x s4).

Explanation / Answer

Ans:

1)Binomial distribution

n=10

p=0.25

2)P(X<5)=BINOMDIST(4,10,0.25,true)=0.9219

use pbinom for part 2,as cumulative distribution function

3)P(2<=X<=4)=BINOMDIST(2,10,0.25,FALSE)+BINOMDIST(3,10,0.25,FALSE)+BINOMDIST(4,10,0.25,FALSE)

=0.2816+0.2503+0.146

=0.6779

for part 3 you can use dbinom and add the probs @ 2,3,4 or use pbinom(4,10,0.25)-pbinom(1,10,0.25)

Excel fucntions are used above,you can use pbinom and dbinom as per given below:

we can use the cumulative probability function for binomial distribution pbinom.

2) pbinom(4, size=10, prob=0.25)
= 0.9219

3)P(2<=X<=4)

=dbinom(2, size=10, prob=0.25) +
+ dbinom(3, size=10, prob=0.25) +
+ dbinom(4, size=10, prob=0.25)

=0.6779

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.