Suppose that y is a random variable having a normal distribution with a mean equal to 250 and a standard deviation equal to 10. Please explain how P(y>230) =P(z>-2)

Q: A normally distributed population with unknown variance has a mean of 20. If you took a random…

A: Given,  X is normally distributed with mean μ=20 and variance is unknown. A random sample of size…

Q: Suppose the area that can be painted using a single can of spray paint is slightly variable and…

A: A continuous random variable X is said to follow Normal distribution with parameters μ and σ2 if its…

Q: Suppose the population of IQ scores in the town or city where you live is bell-shaped, with a mean…

A: Solution-: Let, X= the population of IQ scores in the town Given: We find mean and standard…

Q: You recently took a statistics exam in a large class with n = 500 students. The instructor tells the…

A: Introduction: The empirical rule for a normally distributed random variable is as follows: About…

Q: A large group of students took a test in Statistics and Probability and the final grades have a mean…

A: Given: μ=70 and σ=10. The z-score is calculated as-z=x-μσ

Q: A manufacturer claims that the average lifetime of its lightbulbs is equal to 36 months. A random…

A: Given that  Sample size n =64 Sample mean =32 Population mean =36 Standard deviation =11

Q: In a test taken by a large number of students, the average score of the test takers is 90 and the…

A: P(X>97) = 0.0401 P(X<70) = 0   Total probability = 0.0401

Q: What is the standard error of X⎯⎯⎯X¯ , the mean from a random sample of 25 fill-ups by one driver?…

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Q: Which is true of the distribution of the sample mean?

A: Here given sample of size 20 is taken from a population with a normal distribution and unknown…

Q: A set of exam scores is normally distributed and has a mean of 78.1 and a standard deviation of 8.1.…

A: We have given that , Mean = 78.1 , Standard deviation = 8.1 , X = 60

Q: Compute the values a and b such that the fit of type aX+b provide the desired mean and variance?

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Q: The distribution of raw scores on a chemistry final is approximately normal with a mean of about 50…

A: The random variable X is defined as the student will have a raw score which follows normal…

Q: What proportion of the students scored lower than 80 if the distribution of these grades can be…

A:

Q: Suppose that the annual rainfall in Ferndale, California, is known to be normally distributed, with…

A: Given: The annual rainfall in Ferndale, California, is normally distributed.            Meanμ= 35.5…

Q: An industrial company claims that the mean pH level of the water in a nearby river is 6.8. You…

A: We have given that  Sample size n = 19 Sample mean =6.7 Standard deviation =0.24

Q: In a population, the mean is known to be 1.27 and the standard deviation is known to be 0.351.…

A: The population mean is 1.27; μ=1.27 The population standard deviation is 0.351;σ=0.351 The sample…

Q: The average number of dropouts for a school district has been 305 per year, with a standard…

A: Mean = 305 s = 50

Q: The diameter of bushings produced by a manufacturing process is a normally distributed random…

A: Given information Mean µ = 4.035 mm Standard deviation σ = 0.005 mm n = 25 bushings

Q: Suppose IQ scores of students at Bradley follow a normal distribution with a mean of 103 and a…

A: Calculate the IQ score for the top 2.5% of all IQ's at this college.

Q: For a random sample of 40 students, the average statistics midterm score is 73 points (out of a…

A: The sample size is 40, average statistics midterm score is 73 points, and standard deviation is 7.3.

Q: A simple random sample of 64 observations was taken from a large population. The sample mean and the…

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Q: Assume you have taken 125 samples of size 81 each from a population. The population variance is 64.…

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Q: The critical value for assessing the difference between two proportions at the 0.05 level, or .025…

A: Given: The critical value for assessing the difference between two proportions at the 0.05 level, or…

Q: The owner of a shopping mall wants to estimate the mean length of time shoppers spend in the mall.…

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Q: In a Scrabble tournament, the scores were normally distributed and the mean score was 420.2 points…

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Q: The distribution of SAT scores is normal with a mean of µ = 500 and a standard deviation of σ = 100.…

A: Obtain the SAT score separates the top 25% of the distribution from the rest. The SAT score…

Q: The mean of small dogs is 4.1 and the standard deviation is .9, what is the probability of choosing…

A: The weight of the small dogs is the continuous data.Let X be the weights of the small dogs which…

Q: In a Scrabble tournament, the scores were normally distributed and the mean score was 420.2 points…

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Q: Compute the standard score (Z-score) for x, when x = 42, the mean of the distribution = 26, and the…

A: x = 42Mean = 26Standard deviation = 8

Q: A football coach claims that the average weight of all the opposing teams’ members is 225 pounds.…

A: Given: n= 50.0 ,x̄= 230.0 ,σ= 15.0 µ= 225.0

Q: have a normal distribution. If the mean is 74 and the standard deviation is 2, then a score of 84…

A: From the available information, Population mean, Population  standard deviation, The formula for z…

Q: Roland received a score of 70 on a test for which the mean score was 65.5. Roland has learned that…

A: Given Information: The score Roland received, X = 70. The mean score,μ= 65.5 Z score of the test =…

Q: A population forms a normal distribution with a mean of 85 and a standard deviation of 24 compute…

A: The mean is 85 and the standard deviation is 24.

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: A test was administered for a group of 400 students and scores were obtained. The scores are…

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 test was designed to have a mean of 80 and a standard deviation of 10. A random sample of 20…

A: Computation of test statistic value: The population standard deviation is given, σ = 10. Thus, in…

Q: It is known that the mean is 65 and the standard deviation is 10. There are 30 students in the…

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Q: The standard deviation of a normal random variable X is $50 . Given that P(X ≤ $40) = .25, what is…

A: Given data,σ=50x=40P(X ≤ $40) = .25μ=?

Q: For a random sample of 36 data pairs, the sample mean of the differences was 0.77. The sample…

A: NOTE: Since we only answer up to 3 subparts , we will answer the first 3. Please resubmit the…

Q: Based on the records of the Admissions Office of University X, the mean score of all Grade 11…

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Q: For a normal distribution curve with the mean of 15 and a standard deviation of 5, which range of…

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Q: A researcher wshes to estimate the average blood alcohol concentration (BAC) for drivers involved in…

A: Please note that as per our guidelines we can answer one question only if multiple questions are…

Q: "suppose that a random sample of size 20 is taken from a normal distribution with unknown variance…

A: Given: n=20 μ=Unknownx=10σ2=1Andμ(Posterior)=15σ(Posterior)=0.1

Q: The distribution of raw scores on a chemistry final is approximately normal with a mean of about 60…

A: A z-score represents the position of a data point in terms of its distance from the mean when…

Q: The population average of a college test score of students is 100 with a standard deviation of 25.…

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Q: The change in temperature during the fall fluctuates randomly each day, with mean of -9°, and a…

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Q: The mean score on a standard exam is 320 with a standard deviation of 40. Suppose 100scores are…

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Q: The population average of a college test score of students is 50 with a standard deviation of 10.…

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Q: A population of N=8 scores has a standard deviation of σ=3. What is the value of SS, the sum of the…

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Q: Suppose we have the short hand info on a Normal Distribution as N(10,25). What is the population…

A: Mean:Mean is a measure of center in case of quantitative data. Mean of a data set is the sum of the…

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.