Several psychology students are unprepared for a surprise​ true/false test with 20 questions, and all of their answers are guesses. Find the mean and standard deviation for the number of correct answers for such students.

Q: An aptitude test that is normally distributed has a mean of 1100 and a standard deviation of 100.…

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Q: 3. In order to help the students of a certain school to catch up with the lessons, the faculty…

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Q: For an educational study, a volunteer must place in the middle 50% on a test. If the mean for the…

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Q: A worldwide organization of academics claims that the mean IQ score of its members is 115, with a…

A: mean IQ score of its members is 115 standard deviation of  16 A randomly selected group of 35…

Q: The probability that a patient recovers from a delicate heart operation is 0.85. What is the…

A: Here, p=0.85 and n=7. The general formula for SD is, SD=np1-p

Q: Suppose​ 18% of​ movie-goers say that horror is their favorite movie genre. If a random sample of…

A: Obtain the mean number of movie-goers that prefer horror movie genre. The mean number of movie-goers…

Q: The average score on the SAT is 1020, with a standard deviation of 180. If you take a random sample…

A: We have given that Mean(µ) = 1020 Standard deviation(σ) = 180 Sample size (n) = 50

Q: A person passing through an intersection will find someone running the red light with probability…

A: Obtain the probability that in her next 5 passing through the intersection, she will see no one…

Q: A person must score in the upper 2% of the population on an IQ test to qualify for membership in…

A: From the given information, consider X be a random variable denoting score in an IQ test for…

Q: Suppose the scores, on a college entrance examination are normally distributed with a mean of 1000…

A: We have given that Suppose the scores, on a college entrance examination are normally distributed…

Q: In 1999, the murder rates (per 100,000) for the 50 states and the District of Columbia had a mean of…

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Q: Suppose, you are running an experiment that has two outcomes, namely 'success' and 'failure'. You…

A: Follow Geometric distribution - Let X be number of trials to get first success or X ~ Geo(p)

Q: A population has a standard deviation of σ = 18. On average, how much difference should exist…

A: Given data, σ = 18 n = 4   The standard error measures the distance expected on an average between…

Q: Several psychology students are unprepared for a surprise​ true/false test with 10 ​questions, and…

A: Introduction:If X ~ Bin (n, p), then the probability mass function of X is:p (x) = (nCx) px (1 – p)n…

Q: Suppose it is known that the mean and the standard deviation for a given population are 65 and 8,…

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Q: A researcher wishes to estimate the average height of men for a certain region of the country. If…

A: Probability is the measure determine the likelihood of an event. Event is the outcome of an…

Q: The standard deviation of the scores on a skill evaluation test is 421 points with a mean of 1728…

A: Reviewing information, Given, μ=1728σ=421n=309

Q: A researcher is trying to determine if the av score on a standardized test has decreased. previous…

A: The average and standard deviation of the score is x=97s=6They collect the scores of 74 test…

Q: The president of a university wants to use the mean of a ma to estimate the average amount of time…

A: Given information Standard deviation σ = 1.40 Confidence interval = 0.99 Significance level(α) = 1-…

Q: If a set of numbers has a standard deviation of zero, what can you say about the numbers?

A: The standard deviation indicates that amount of deviation of data points from the mean.

Q: A psychologist who needs two groups of students for a learning experiment decides to select a…

A: Hi! Thank you for the question. AS per the honor code, we are allowed to answer the three sub-parts…

Q: The principal decided that the top 30% of the class with the highest grades in statistics will be…

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Q: The manufacturer of cans of salmon that are supposed to have a net weight of 6 ounces tells you that…

A: GivenMean(μ)=6.04standard deviation(σ)=0.21Sample size(n)=33

Q: Customers are considered very satisfied with the XYZ Box video game system if the mean of the…

A: 1.Denote X as the mean of all the satisfaction ratings. It is given that X is distributed, with mean…

Q: . In order for an engineering graduate to enroll in a master’s program, the graduate studies…

A: GivenMean(μ)=420standard deviation(σ)=100

Q: The scores for a standardized reading test are found to be normally distributed with a mean of 300…

A: Given : mean = μ = 300 standard deviation = σ = 40 sample size = n = 490

Q: A village head wants to know the number of chickens in his area. So the Lurah conducted research on…

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Q: An anthropologist wishes to estimate the average height of the inhabitants of a certain region. If…

A: Obtain the probability that the difference between the sample mean and true population mean will not…

Q: due to the increasing price of apartments each year, houston chronicle reported that rent of 1 bed 1…

A: Given that  μ=1200σ=500n=20 Consider, the probability that the price is more than 1100 is,…

Q: A population is normally distributed and has a mean of 50 and a standard deviation of 5 If we…

A: As we know the empirical rule of 68 - 95 - 99.7 that is the percent value that are one, two or three…

Q: A recent study found that 69% of all adults over 50 wear sunglasses for driving. In a random sample…

A: Formula : Mean = np Standard Deviation  :

Q: Suppose 36% of movie goers say comedy is their favorite genre. If a random sample of 120 movie goers…

A: Obtain the mean number of movie goers that prefer comedy. The mean number of movie goers that prefer…

Q: For a group of 100 candidates the mean and standard deviation of their marks were found to be 60 and…

A: 1] n=100 2] X¯=603] Standrd deviation σ=154] σ2=225

Q: The results of a common standardized test used in psychology research is designed so that the…

A: Given Information: Population mean (u) = 165  Standard deviation (σ) = 10  Score earned by a subject…

Q: In a normal PD, the mean equals 1100 and the standard deviation equals 80. If you choose a sample of…

A: Solution: Let X be the random variable. From the given information, X follows normal distribution…

Q: An airliner carries 350 passengers and has doors with a height of 72 in. Heights of men are normally…

A: From the given information, let X be the men passengers height. Number of men passengers n = 175.…

Q: The mean of a test is 86 with a standard deviation of only 4. How likely (what probability) is there…

A: Let X= score  Given, X follows normal distribution with mean = 86 and standard deviation = 4

Q: A psychologist believes that it will take at least an hour for certain special child to learn a…

A: Given,sample size(n)=30sample mean(x¯)=50population standard deviation(σ)=15α=0.01

Q: There is an 85% chance that a randomly selected person will take their own re-usable bags to the…

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Q: A certain data set has a mean of 60 and a standard deviation of 12. Given that the data set has 120…

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Q: A food safety engineer has discovered that a food warmer has temperature problems. While they set up…

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Q: Based on various studies, it is known that the mean ACT-math score in America is 21 with a standard…

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Q: For example, the value of the results of a Physics test. The mean is 77 and the standard deviation…

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Q: What is the z-score of x=9, if it's 1.5 standard deviations to the left of the mean

A: We have to find z value from given data

Q: Given a set of data that is skewed-right, there is at least _____ % of the data within 2 standard…

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Q: Suppose it is known that the average score of all high school seniors taking a national test of…

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Q: two fifth grade classes have nearly identical mean scores on an aptitude test, but one class has a…

A: It is given that two fifth grade classes have nearly identical mean scores on an aptitude test, and…

Q: If the distribution of the population has a nonzero standard deviation and mean 12 then the…

A: It is given that the population has a nonzero standard deviation and the mean is 12.

Q: A variable is normally distributed with a mean of 120 and a standard deviation of 5. Four scores are…

A: Given information- Population mean, μ = 120 Population standard deviation, σ = 5 Since it is…

Q: If there are ten values each equal to 10, then standard deviation of these values is:

A: Standard deviation determines how the individual values of the data deviate from the value of mean.…