A quiz consists of 20 multiple choice questions, each with five possible answers, only one of which is correct. If a student guesses on each question, what is the mean and standard deviation of the number of correct answers

Q: 5. Thirty-two percent of adult Internet users have purchased products or services online. For a…

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Q: According to a Boston Globe story, only about 1 in 6 Americans have blue eyes, whereas in 1900 about…

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Q: A video game company sells an average of 132 games a month per store, with a standard deviation of 9…

A: Given,mean(μ)=132standard deviation(σ)=9sample size(n)=36

Q: According to a 2017 Wired magazine article, 40% of emails that are received are tracked using…

A: a. Let the variable X is defined as the number of emails that are tracked which follows binomial…

Q: If 80% of the applicants are able to pass driver’s proficiency road test, find the mean, variance,…

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Q: Seven students on an intramural team weigh 179 lb, 172 lb, 174 lb, 185 lb, 162 Ib, 181 Ib and 193…

A: According to the provided information, the sample weights are 179, 172, 174, 185, 162, 181, 193

Q: Ojai is a weather station in the state of California and Seabrook is a weather station in the state…

A: Given information- We have given the data of noontime temperatures recorded among weather stations…

Q: The mean life of a battery is 50 hours with a standard deviation of 6 hours. The manufacturer…

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Q: The grades of a statistics midterm are normally distributed with a mean of 70 and a standard…

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Q: 5 Colton and Jake began arguing about who did better on their tests, but they couldn't decide who…

A: Given information English class Colton Marks x = 72.9 Mean µ = 76.7 Standard deviation σ = 8.9 Art…

Q: An airline charges $25 for the first bag, $35 for the second bag 54% have no checked baggage,  34%…

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Q: At a supermarket, the mean waiting time to get to the checkout counter is 5 minutes and the standard…

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Q: Suppose that a large Introduction to Psychology class has taken a midterm exam, and the scores are…

A: (1) Obtain the proportion of the class got scores above 90. The proportion of the class got scores…

Q: The monthly utility bills in a city are normally​ distributed, with a mean of ​$100 and a standard…

A: Let X be the random variable from normal distribution with mean (μ) = 100 and standard deviation (σ)…

Q: Here are 6 celebrities with some of the highest net worths (in millions of dollars) in a recent…

A: In a set of data, a range is defined as the difference between the highest value in the data set and…

Q: If heads is a success when we flip a coin, getting a six is a success when we roll a die, and…

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Q: A professor who teaches a large introductory statistics class (197 students) with eight discussion…

A: As due to the honor-code, we are authorized to answer only 3 subparts for each question and that…

Q: A machine produces electrical components. 99.7% of the components have lengths between 1.176 cm and…

A: Given 99.7% components length lies between 1.176 and 1.224 m Using empericals rule we know that…

Q: . Defective DVDS From past experience, a company found that in cartons of DVDS, 90% contain no…

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Q: A set of final examination grades in an introductory statistics course is normally dis-tributed with…

A: Given that  Mean=mu=79 Standard deviation=sigma=12 X~Normal (mu=79,sigma=12) Note: According to…

Q: Janai and Aaliyah began arguing about who did better on their tests, but the decide who did better…

A: GivenJanai earned in Math is 76.5 Aaliyah earned in social studies = 70.2For…

Q: In physics examination, the mean grade is 80 and the standard deviation is 5. a. Find the…

A: Solution-: Given:  Let, X- Score (grades) of examination (a) Find the corresponding z-scores of two…

Q: A study of the amount of time it takes a mechanic to rebuild the transmission for a 2005 Chevrolet…

A: Given,mean(μ)=8.4standard deviation(σ)=1.8sample size(n)=40

Q: A final exam in Math 160 has a mean of 73 with a standard deviation of 7.8. If 24 students are…

A: Given n=24 Mean=73 Standard deviation=7.8

Q: In your two sets of Statistics tests, find the mean of the number of tests that will be passed. 1.…

A: Given: The provided dataset is given as: Number of passed test (x) Probability P(x) 0 0.25 1…

Q: If the mean of a random variable is 30 and the standard deviation is 6 , and three consecutive data…

A: It is given that, Mean,μ=30 Standard deviation,σ=6

Q: You are an educational researcher at McMaster University. Suppose you know that 22.7% of the entire…

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Q: A&W offers a meal deal if you get burgers and fries. Within North America 65% of A&W customers opt…

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Q: are recalculated, which of the following four (4) statements are false? (i) The new mean will be…

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Q: Skye High School has a total of 500 graduates.  The mean SAT score of Skye High School graduates is…

A: Given data,μ=947σ=205P(X≥1000)=?

Q: The average drive to work is 9.6 miles. Assume the standard deviation is 1.8 miles. If a random…

A: From the given information, x¯=9.6σ=1.8n=36

Q: The average baggage-related revenue per passenger is: $  (please round to the nearest cent) b) The…

A: An airline charges the following baggage fees: $20 for the first bag and $35 for the second. Suppose…

Q: 1. Suppose 30 students were chosen randomly, what is the probability that their mean IQ score is…

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Q: The results of a nationwide aptitude test in mathematics are normally distributed with 80 as the…

A: Solution

Q: The probability that a patient recovers from a delicate heart operation is 60%. There are 20…

A: Given data: Probability  = p = 0.60 Sample size (n) = 20 To find: What is the mean and standard…

Q: In terms of skewness, what does it mean if more values are concentrated above the mean? In this…

A: Solution Given more values are concentrated above the mean . So Median will lies right  side to the…

Q: A researcher wishes to estimate within $20 the average cost of postage a community college spends in…

A: GivenMargin of error(E)=20standard deviation(σ)=60confidence level = 90%

Q: people were given three cups of water to taste. One was bottled water and the other two were tap…

A: The probability that student will guess the correct bottled water will be: p=13

Q: A sample of twenty people went on a cruise to Europe. Their two-week weight gain is shown below (a…

A: Solution: We find what weight gain is 3 standard deviations above the mean (in pounds)?

Q: According to a study, the salaries of registered nurse are normally distributed with a mean of 56310…

A: Given,mean(μ)=56310standard deviation(σ)=5038

Q: wo students, Donald and Martin, want to find out who has the higher GPA when compared to each of…

A: Ƶ -score for Donald is   Ƶ = x¯-μσ       = 3.85-3.250.4Ƶ = 1.5

Q: a survey found that 21% of Americans watch fireworks on television on July 4.  Find the mean,…

A: According to the given question, a survey found that 21% of Americans watch fireworks on television…

Q: A pharmaceutical company claims that its new medication results in side effects for 20% of those…

A: n = 100 p = 0.2

Q: 4. The variance of a data set is 3410.56. Find the standard deviation for the data set.

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Q: There are only 4 teams in a league. The winning percentages of the teams are given as follows: Team…

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Q: According to a Boston Globe story, only about 1 in 6 Americans have blue eyes, whereas in 1900 about…

A: a. In a Boston Globe story, it is states that out of 6 Americans, 1 has blue eyes.  The sample size,…

Q: 15. The standard deviation of all possible sample means equals

A: Our Aim is to tell what is equals to the standard deviation of all possible sample means ?

Q: An airline charges the following baggage fees: $25 for the first bag and $40 for the second. Suppose…

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Q: . Each member of a large genetics class grows 12 pea plants from an independent pea family. Each…

A: Total pea plants (n) = 12 Proportion of smooth pea plants = 3/4 Proportion of wrinkled pea plants =…

Inverse Normal Distribution

The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.

Mean, Median, Mode

It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.

Z-Scores

A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.