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Assume that random guesses are made for six multiple choice questions on an SAT test, so that there are n = 6 trials, each with probability of success (correct) given by

p=0.35. Find the indicated probability for the number of correct answers.
Find the probability that the number of correct answers is fewer than 4.
P(X<4)=0
(Round to four decimal places as needed)

User Mizux
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2 Answers

1 vote

Final answer:

To calculate the probability that the number of correct answers is fewer than 4 on a 6-question multiple choice test with each question having a probability of correct answer p=0.35, use the binomial probability distribution either by calculating individual probabilities for 0, 1, 2, and 3 correct answers and adding them together, or using the cumulative binomial probability function on a calculator.

Step-by-step explanation:

To find the probability that the number of correct answers is fewer than 4 (P(X<4)) when making random guesses on a six-question SAT test where the probability of getting a question right is 0.35, we can use the binomial probability formula or a calculator with binomial distribution functions.

Use the formula P(X = x) = (nCx) * (p^x) * ((1 - p)^(n-x)), where:

  • n is the number of trials (6 in this case),
  • p is the probability of success on a single trial (0.35), and
  • x represents the number of successful trials.

Calculate the probabilities for x being 0, 1, 2, and 3 and add them up.

Alternatively, use a calculator function like binomcdf for cumulative probabilities: P(X < 4) = binomcdf(6, 0.35, 3).

User Aahnik
by
3.7k points
4 votes

Answer:

0.9830 = 98.30%

Step-by-step explanation:

User Bereal
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3.1k points