Question

In: Statistics and Probability

Consider a binomial distribution of 200 trials with expected value 80 and standard deviation of about...

Consider a binomial distribution of 200 trials with expected value 80 and standard deviation of about 6.9. Use the criterion that it is unusual to have data values more than 2.5 standard deviations above the mean or 2.5 standard deviations below the mean to answer the following questions.

(a) Would it be unusual to have more than 120 successes out of 200 trials? Explain.

Yes. 120 is more than 2.5 standard deviations above the expected value.

Yes. 120 is more than 2.5 standard deviations below the expected value.

No. 120 is less than 2.5 standard deviations above the expected value.

No. 120 is less than 2.5 standard deviations below the expected value.

(b) Would it be unusual to have fewer than 40 successes out of 200 trials? Explain.

Yes. 40 is more than 2.5 standard deviations above the expected value.

Yes. 40 is more than 2.5 standard deviations below the expected value.

No. 40 is less than 2.5 standard deviations above the expected value.

No. 40 is less than 2.5 standard deviations below the expected value.

(c) Would it be unusual to have from 70 to 90 successes out of 200 trials? Explain.

No. 70 to 90 observations is within 2.5 standard deviations of the expected value.

Yes. 70 to 90 observations is within 2.5 standard deviations of the expected value.

No. 90 observations is more than 2.5 standard deviations above the expected value.

Yes. 70 observations is more than 2.5 standard deviations below the expected value.

Solutions

Expert Solution

1:- Standard Deviation is 6.9
2:- Standard Deviations are 13.8

Any number that is more than 13.8 away from the mean of 80 would be unusual.
80 - 13.8 = 66.2
80 + 13.8 = 93.8

Expected would be in the range 66.2 to 93.8.
Unusual would be a score below 66.2 or above 93.8.

(a) Would it be unusual to have more than 120 successes out of 200 trials? Explain.

120 is above 93.8 so that is definitely unusual.

Because

Yes. 120 is more than 2.5 standard deviations above the expected value.

(b) Would it be unusual to have fewer than 40 successes out of 200 trials? Explain.

40 is below 66.2 so that is definitely unusual .

Because   

Yes. 40 is more than 2.5 standard deviations below the expected value.

(c) Would it be unusual to have from 70 to 90 successes out of 200 trials? Explain.

70 and 90 are in the range and are not considered unusual.

Because 70 to 90 is within the range   

No. 70 to 90 observations is within 2.5 standard deviations of the expected value.


Related Solutions

What would be the value of the mean for a binomial distribution that 141 trials and...
What would be the value of the mean for a binomial distribution that 141 trials and a success probability of 0.19? What would be the value of the mean for a binomial distribution that 186 trials and a success probability of 0.68? What would be the value of the mean for a binomial distribution that 80 trials and a success probability of 0.49? What would be the value of the mean for a binoial distribution that 175 trials and a...
Distribution A has an expected value of $50 and a standard deviation of $100; distribution B...
Distribution A has an expected value of $50 and a standard deviation of $100; distribution B has an expected value of $75 and a standard deviation of $125. Ignoring preferences over risk, which is the better option? 1) A 2) B 3) They are the same 4) It is impossible to tell
True or false. Consider a binomial distribution with 16 trials. Look at a table showing binomial...
True or false. Consider a binomial distribution with 16 trials. Look at a table showing binomial probabilities for various values of p, the probability of success on a single trial. For small values of p, the distribution is skewed to the right.
Find the expected value, μ, and standard deviation, σ, for a binomial random variable with each...
Find the expected value, μ, and standard deviation, σ, for a binomial random variable with each of the following values of n and p. (Round all answers for σ to four decimal places.) (a) n = 40, p = 1/2. μ = σ = (b) n = 100, p = 1/4. μ = σ = (c) n = 2500, p = 1/5. μ = σ = (d) n = 1, p = 0.1. μ = σ = (e) n =...
Consider a binomial experiment. If the number of trials is increased, what happens to the expected...
Consider a binomial experiment. If the number of trials is increased, what happens to the expected value, if the number of trials is decreased, what effect would occur? With regard to the standard deviation, illustrate how and why the larger the deviation number, the more difficult it would be to predict an outcome. Use specific examples to illustrate.
Calculate (by hand) the mean and standard deviation for the binomial distribution with the probability of...
Calculate (by hand) the mean and standard deviation for the binomial distribution with the probability of a success being 0.50 and n = 10. Either show work or explain how your answer was calculated. Use these formulas to do the hand calculations: Mean = np, Standard Deviation =  Comparison: Calculate (by hand) the mean and standard deviation for the binomial distribution with the probability of a success being 0.10 and n = 10. Write a comparison of these statistics to those...
A distribution of values is normal with a mean of 80 and a standard deviation of...
A distribution of values is normal with a mean of 80 and a standard deviation of 18. From this distribution, you are drawing samples of size 12. Find the interval containing the middle-most 88% of sample means: Enter your answer using interval notation. In this context, either inclusive or exclusive intervals would be acceptable. Your numbers should be accurate to 1 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.
A distribution of values is normal with a mean of 80 and a standard deviation of...
A distribution of values is normal with a mean of 80 and a standard deviation of 18. From this distribution, you are drawing samples of size 13. Find the interval containing the middle-most 32% of sample means: Incorrect Enter your answer using interval notation. In this context, either inclusive or exclusive intervals would be acceptable. Your numbers should be accurate to 1 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted.
Find the mean, variance, and standard deviation of the binomial distribution with the given values of n and p. n=80, p=0.4
Find the mean, variance, and standard deviation of the binomial distribution with the given values of n and p. n=80, p=0.4 The mean, μ, is _______  (Round to the nearest tenth as needed.) The variance, σ2, is _______ (Round to the nearest tenth as needed.) The standard deviation, σ, is _______ (Round to the nearest tenth as needed.)
Given the following discrete uniform probability distribution, find the expected value and standard deviation of the...
Given the following discrete uniform probability distribution, find the expected value and standard deviation of the random variable. Round your final answer to three decimal places, if necessary. Probability Distribution x 0 1 2 3 4 5 6 7 8 9 10 P(X=x) 1/11 1/11 1/11 1/11 1/11 1/11 1/11 1/11 1/11 1/11 1/11
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT