Alex wants to find out: if the standard deviation of the mean for the sampling distribution of random samples of size 256 from a large or infinite population is 9, how large must the sample size become if the standard deviation is to be reduced to 2.7 (or even smaller)?

Q: For a sample of n = 30 scores, a score that is 6 points above the mean has a z-score of z = 1.50.…

A: For a sample of n = 30 scores, a score that is 6 points above the mean has a z-score of z = 1.50.

Q: The weights of men in a particular age group have mean ? = 176 pounds and standard deviation ? = 36…

A: The random variable X follows normal distribution. We have to find the standard error of the mean…

Q: f the height of Grade 6 pupils is normally distributed with a mean of 64 in. And a standard…

A: The z-score is calculated asz=x-μσ

Q: For a sample with M= 80, a score of X= 88 corresponds to z =2. what is the sample standard deviation…

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Q: According to the rules of probability, if a sampling distribution has a standard error of .45, the…

A: Solution: From the given information, the standard error of the sampling distribution is 0.45.

Q: If the standard error (σX) of the mean distribution is 10 and the sample size is 25, then what is…

A: Given information Standard error of the mean distribution = 10 Sample size = 25

Q: A National Center for Health Statistics survey suggested that, in the late 1970s, the mean serum…

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Q: In a sample distribution, X=56 corresponds to z=1.00, and X=47 corresponds to z=-0.50. Find the mean…

A: Given,  X=56 corresponds to z=1.00 X=47 corresponds to z=-0.50 wktz=x-μσX=zσ +μ

Q: For a population with mean of 50 and standard deviation of 8, what is the z-score that corresponds…

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Q: For a sample with mean M=80,  a score of X=88 corresponds to z=2. What is the standard deviation?

A:

Q: The law of large numbers tells us that as sample size n increases: the sample standard deviation…

A: Correct answer is (c). The sample mean approaches the population mean.

Q: (d) If the sample size is n= 16, what is the standard deviation of the population from which the…

A: Using central limit theorem.

Q: For example with m= 80, a score of x = 88 corresponds to z = 2.00.  What is the sample standard…

A: GivenMean(M)=80x=88z-score(z)=2.00

Q: A sample of n = 5 scores has ΣX = 20 and ΣX2 = 180. For this sample, what is the value of the sample…

A: According to the provided information,   n = 5  ΣX = 20 ΣX2 = 180

Q: Suppose that the percentage of defective items on a certain production line is 15%. Draw 8 items at…

A: Given ,n=8p=0.15X=no.of defective itemsX~Binomial(n=8 , p=0.15)P(X=x)=cxn  px (1-p)n-x  ;…

Q: Suppose that the scores on a statewide standardized test have a bell shape distribution with a mean…

A: Given that Mean = 79,s.d=6 (b) P(X>97 )=? (c) P(X<73) =? (d)P(61<x<85) =?

Q: A student learns that on his most recent exam in psychology, the sample mean was 72.19 with a…

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Q: . For a population with a mean of µ = 70, a score of X = 64 corresponds to z = -1.50. What is the…

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Q: A scientist has read that the mean birth weight, , of babies born at full term is 7.5 pounds. The…

A: a) Null and Alternate Hypothesis: H0: μ=7.5H1: μ>7.5 Therefore, H0: μ is equal to 7.5 H1: μ is…

Q: A professor finds that the grades in a large class are normally distributed. The mean of the grades…

A: It is given that mean is 64 and standard deviation is 10.

Q: Choose the correct answer below. O A. No, because in this situation the distribution is skewed to…

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Q: Suppose you know that the distribution of sample proportions of nonresidents in samples of 200…

A: Let p^ denotes the sample proportion which follows normal distribution with mean 0.46 and standard…

Q: A researcher wishes to determine how much money per week is spent on groceries in a small Western…

A: Given : ME< 3.0 σ= 18.0 At 98.0 % confidence level , z score= 2.326 Need to find the minimum…

Q: According to the Nielsen Company, the mean number of TV sets in a U.S. household in a recent year…

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Q: If the average low temperature of a winter month in Rochester, NY is 16° and the standard deviation…

A: The Chebyshev’s inequality theorem states that of the data values falls inside the k standard…

Q: For a random sample of 9 women, the average resting pulse rate is x-bar = 76 beats per minute, and…

A:

Q: 2. Suppose that in an examination, the cut-off score for passing is 75 for 200 persons. If the mean…

A: Given that, Suppose that in an examination, the cut-off score for passing is 75 for 200 persons. If…

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: A large normally distributed population has a mean of 502 and a standard deviation of 25. If the…

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Q: A sample of n = 5 scores has Σ X = 20 and Σ X2 = 180. For this sample, what is the value of the…

A:

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: Hello, how do you calculate this? Thank You!

A: Compute the 90% confidence interval for the population mean.Since the sample size is small and the…

Q: Suppose that for a random sample , the mean is 4 and the coefficient of variation is 87.5 % then the…

A:

Q: In the general population, the mean IQ is 100 with a standard deviation of 15. Dr. Robbins wants to…

A: From the provided information, Population mean (µ) = 100 Population standard deviation (σ) = 15

Q: For a random sample of 10 men, the mean head circumference is x-bar= 57.3 cm and the sample standard…

A:

Q: Given a scenario where n=100 and p=0.8, find the standard deviation.

A: In this case the sample size is n = 100 and p = 0.8.

Q: For a normally distributed population with a mean of 35 and a standard deviation of 7.5, what value…

A: X follows a Normal distribution with mean = 35 and S.D = 7.5 Then z=(x-mean)/SD = (x-35)/7.5…

Q: John wishes to estimate the population standard deviation of salary of college graduates who took a…

A: Standard deviation is the positive square root of the mean of the squared deviations of given…

Q: For a sample of n = 20 scores, X = 25 corresponds to z = -1.20 and X = 40 corresponds to z = +1.80.…

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Q: If X is a normally distributed random variable with a mean of 235 Find the standard deviation given…

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Q: The population of SAT scores forms a normal distribution with a mean of μ = 500 and a standard…

A:

Q: (O) What is the standard deviation of a distribution that has a mean of 46.2 if a PERFORMANCE value…

A: From the provided information, Mean (µ) = 46.2 Performance value (x) = 28 Z score = -1.24

Q: For a sample from a normal distribution with standard deviation σσ, the standard deviation of the…

A:

Q: A population has a standard deviation of  = 30. A. On average, how much differences should exist…

A: Given Standard deviation (σ) = 30Sample size (n) = 4and standard error = σn…

Q: For a population with mean of 50 and standard deviation of 8, what is the z-score that corresponds…

A: Given that , mean = μ = 50 standard deviation = σ = 8 x = 46

Q: The weights of men in a particular age group have mean ? = 186 pounds and standard deviation ? = 20…

A: Solution

Q: For a population with mean of 50 and standard deviation of 8, what is the z- score that corresponds…

A:

Q: In a sample distribution, a score of x = 21 corresponds to z = -1.00 and a score of x = 12…

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: For a random sample of 10 men, the mean head circumferences are x-bar = 57.3 cm, and the sample…

A: Given data:   The given sample size is n=10. The given mean head circumference is x=57.3 cm. The…

Q: Suppose that the scores on a statewide standardized test are normally distributed with a mean of 68…

A: As per our guideline we are supposed to answer only  3 sub-parts of any question