The national scores on an exam were normal distributed with a mean of 428 and a standard deviation of 113. Approximately what percent of those taking this test had scores between 315 and 541?

Q: On a statistics exam, the mean score was 80 and there was a standard deviation of 7. If a student's…

A: Given data, μ=80σ=7If x=92z=?

Q: Suppose the exam average in a class is 72% with a standard deviation of 3. What proportion of…

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Q: The heights of men, in centimetres, are normally distributed with a mean of 175 and a standard…

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Q: The mean grade on a science test was 79 and there was a standard deviation of 6. If your sister…

A: The z score explains the deviations of the observations from the mean. It is calculated using the…

Q: The scores of the students in the final examination in Advanced Algebra are normally distributed…

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Q: A test has a mean of 140 and a standard deviation of 27. What proportion of people have scores…

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Q: On a national achievement test score was 850 with a standard deviation of 100. What proportion of…

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Q: The mean score on the verbal section of the SAT in a certain year was 505 with a standard deviation…

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Q: A z-score of −1 tells us that a score fell one standard deviation below the mean in a group of…

A: Empirical rule: For a normal distribution, the approximate values that fall in the specified…

Q: Scores on a recent national statistics exam were normally distributed with a mean of 80 and standard…

A: Obtain the standard z-score for X equals 89 The standard z-score for X equals 89 is obtained below:…

Q: Students at Arrowhead High School took an English test with a mean of 120 and a standard deviation…

A: Let X be a random variable of normal distribution with mean 120 and standard deviation 25.  Let Z be…

Q: 1. On a final examination in Mathematics, the mean was 76 and the standard deviation was 5.…

A: Since you have asked multiple questions, we will solve the first question for you. If you want any…

Q: The scores on a standardized test are approximately normal with a mean of 83 and a standard…

A: Let T be minimum score needed to be in top 8%

Q: the mean weight of a group of boys is 145 lb, with a standard deviation of 4lb. if the weights are…

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Q: Which is better a score of 91 on a test with a mean of 81 and a standard deviation of 15, or a score…

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Q: In 2019, the amount of money that motorists spent on gas had a normal distribution with a mean of…

A: Given Information Number of persons sampled (n) = 2400 Mean (µ) = 900 Standard deviation(σ) = 100…

Q: The grades on a test follow a normal distribution with a mean mark of 70 and a standard deviation of…

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Q: on a national achievement test score was 850 with a standard deviation of 100. what proportion of…

A: The Z-score of a random variable X is defined as follows: Z = (X – µ)/σ. Here, µ and σ are the mean…

Q: A college entrance exam scores are approximately normally distributed with a mean value of 145 and a…

A: Solution: Let X be the college entrance exam score. From the given information, X follows normal…

Q: The vocabulary test scores for the population of third graders is normally distributed with a mean…

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Q: The distribution of scores is approximately normal with a mean of 31 and a standard deviation of 5.…

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Q: A normal distribution has a mean of 60 and a standard deviation of 20. Barbara's score is 40. What…

A: It is given that the Normal distribution has a mean 60 and a standard deviation of 20.  Suppose X be…

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 122…

A: Given data,Mean μ=122sd σ=16

Q: In a Science test, the mean score is 42 and the standard deviation is 5. Assuming the scores are…

A: Given: The mean score of a Science test is μ=42. The standard deviation is σ=5. Let X be a random…

Q: he scores on a psychology exam were normally distributed with a mean of 65 and a standard deviation…

A: Given,μ=65σ=6

Q: A class midterm had an average score of 75% with a standard deviation of 4%. Based on your answer…

A: Unusual: When z-score is less than -1.5 and greater than 1.5 then the event is said to unusual. The…

Q: The test scores for a very large statistics class have a bell-shaped distribution with a mean of 72…

A: We have given that  X~N(mu, sigma^2) mu = 72  Z-score =(x-mu )/sigma

Q: In 1970, adults who were 18 years or more had a mean systolic blood pressure (SBP) of 148 mm Hg.,…

A: Given that in 1970 adults who were 18 years or more had a mean systolic blood pressure (SBP) of 148…

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 118…

A: Note: Please repost d subpart as i can answer only 3 subparts as per my policy. Given data,…

Q: Which is better a score of 92 on a test with a mean of 71 and a standard deviation of 15, or a score…

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Q: The scores on a psychology exam were normally distributed with a mean 56 of  and a standard…

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Q: Which is better a score of 95 on a test with a mean of 70 and a standard deviation of 15, or a score…

A:

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 119…

A: Given data,μ=119σ=16P(X≥160)=?

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 121…

A: X follows a Normal distribution with mean = 121 and S.D = 19 Then z=(x-mean)/SD = (x-121)/19…

Q: Suppose the exam average in a class is 55% with a standard deviation of 4. What proportion of…

A: The random variable score follows normal distribution. The population mean is 55.         The…

Q: the mean weight of a group of boys is 145 lb, with a standard deviation of 5lb. if the weights are…

A: We have to find correct answer..

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 119…

A: The mean of the blood pressure is 119. The standard deviation of the blood pressure is 23.

Q: The heights of people are normally distributed with a mean of 86 inches and a standard deviation of…

A: X follows a Normal distribution with mean = 86 and S.D = 5 Then z=(x-mean)/SD = (x-86)/5  follows…

Q: A grade of 81 in a test in which the mean is 75 and the standard deviation is 12 corresponds to a…

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Q: The scores on a psychology exam were normally distributed with a mean of 64 and a standard deviation…

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Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 122…

A: Given that, The systolic blood pressure of adults in the USA is nearly normally distributed with a…

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 121…

A: Here the systolic blood pressure of US adults is normally distributed with mean=121 and SD=21. Also…

Q: The scores on a psychology exam were normally distributed with a mean of 55 and a standard deviation…

A: Find the percentage of scores that are less than 37.

Q: An instructor in a large lecture class found, at the end of the semester, that the total point…

A: It is given that mean and standard deviation are 530 inches and 80, respectively.

Q: Suppose the exam average in a class is 82% with a standard deviation of 6. What proportion of…

A: Here, mean is 82 and standard deviation is 6.

Q: The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 118…

A: The parameter {\displaystyle \mu } is the mean  or expectation  of the distribution (and also its…

Q: The scores for all high school seniors taking the verbal section of the Scholastic Aptitude Test…

A: Given distribution is bell shaped. In bell shaped distribution mean, median and mode are equal.…

Q: A statistics professor announces that 15% of the grades he gives are As.  The results of the final…

A: Solution:From the given information, mean score is 83, standard deviation is 6. The fifteen…

Q: Suppose a class average on a test is 75 and the standard deviation is 10. if joe scores 80 on the…

A: