A researcher believes at 49% of people who grew up as the only child have an IQ score over 100. However, unknown to the researcher this figure is actually 50% which is the same as the general population. To attempt to find evidence for the claim, the researcher is going to take a random sample of 400 people who grew up as an only child. Let X be the

Q: Mean of 100 observations is found to be 40. If at the time of computation two items are wrongly…

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Q: Consider the variable x = time required for a college student to complete a standardized exam.…

A: The proportion of students at this university would be unable to finish in the allotted time when 50…

Q: A sample has a mean of 30 and s=8 would a score of x=36 be considered a central score or an extreme…

A: The z-score for x=36 when mean of 30 and standard deviation of 8 is, z=x-Means=36-308=68=0.75 It is…

Q: The population mean will always be the same as the mean of all possible X that can be computed from…

A: Given : The population mean will always be the same as the mean of all possible X that can be…

Q: A set of N = 10 scores has a mean of µ = 50.  If 20 points are added to one of the scores, what is…

A: It is given that the number of scores in the set is 10 and the population mean is 50.

Q: What is the z score of x=30 if x is three deviations to the left of the mean?

A: From the provided information, x = 30 and it is three deviations to the left of the mean.

Q: Using z scores, a population with u = 37 and o = 6 is standardized so that the new mean is u = 50…

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Q: A sample of n = 6 scores has a mean of m = 5. one person with a score of x = 19 is added to the…

A: Sample size (n) = 6Mean(m)  =5

Q: You want to determine whether there is a significant difference in the use of cell phone…

A: From the provided information,

Q: A sample of n=8 scores has a mean of M=7. If one score is changed from X =20 to X =4, what is the…

A: Consider the first 7 scores is x1, x2, x3, x4, x5, x6, x7 and the 8th score is, x8=20. The formula…

Q: A sample of n=5  scores has a mean of M=12. If one new score with a value of  X=18 is added to the…

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Q: Find the raw score for 99% with a population mean of 29 and σ of 4?

A: Mean()=29standard deviation()=4

Q: In calculating the moments of a frequency distribution based on 100 observations, the following…

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Q: A sample of n=5 scores has a mean of M = 12. if one new score with a value of x =17 is added to the…

A: Given information n=5 Mean M=12 Formula of mean is given by M=∑xin Where, xi are data points and n…

Q: random sample of about 1000 people to estimate the mean of some quantity over a population of…

A: A confidence interval estimate is an interval estimate that includes the unknown population…

Q: A score that is 3 points lower than the sample mean has a z-score of z = -0.25, and a score of X =…

A: Given information: Case-1: z = -0.25  Score (X) = u-3  Sample mean (u) = u  Case-2: z = -0.75  X =…

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: (a) Find the mean of p, where p is the proportion of people with IQ scores over 100 in a random…

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Q: A sample of n = 15 scores ranges from a high of X = 11 to a low of X = 3. If these scores are placed…

A: Given: Lowest value of X = 3 Highest value of X = 11

Q: f n=7 scores has a mean of u=13. What is the value of EX

A: The formula of the mean is: Meanμ = ΣX N

Q: You want to determine whether there is a significant difference in the use of cell phone…

A: The test statistic, t=x¯-y¯S1n1+1n2~tn1+n2-2where, x¯=mean of first sample            y¯=2nd sample…

Q: A sample of n = 5 scores has a mean of X-bar = 9. What is ∑X for this sample?

A: From the provided information, Sample size (n) = 5 Mean (x̅) = 9

Q: Using z-scores, a population with u = 37 and o = 6 is standardized so that the new mean is u = 50…

A: Given

Q: If 3 standard deviations to the left of the mean gives you a value of 30 on the normal curve and 4…

A: 3 standard deviations to the left of the mean=30i.e and 4 standard deviations to the right of the…

Q: he margin of error for a 90% CI for a mean, when the sample size is 12, the sample average is 52,…

A: As the population standard deviation is known, we will use t distribution. Degrees of freedom =…

Q: What percentage of all possible observations of the variable lie between 1/4 and 5/8

A: Let us first assume that the total proportion is from 0 to 1. The proportion lying between 1/4 and…

Q: ome up with the 90% confidence interval for the difference.

A: Given that  A researcher surveyed 677 college men and 587 college women.  498 of the college men…

Q: You want to determine whether there is a significant difference in the use of cell phone…

A: Given that, Y1 bar = 5 N1= 20 Standard deviation, S1= 1.07 Y2 bar= 6 N2= 15 Standard deviation, S2=…

Q: A population of N= 10 scores has a mean ofµ=6. After one score is removed, the mean is found to be…

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Q: tion, the standard distance between a sample mean and the population mean is 5 points for samples of…

A: The formula of standard error: SE=sn Now,  the standard distance between a sample mean and the…

Q: population of N = 10 scores has a mean of µ = 6. After one score is removed, the mean is found to be…

A: given data  population size (N) = 10 population mean ( μ) = 6 after removing one score : new mean =…

Q: if the variance of the water temperature in a lake is 28°, then for how many days would a researcher…

A: It is given that margin of error (E) is 3 and the confidence level is 99%.

Q: The population mean will always be the same as the mean of all possible X¯ that can be computed from…

A: We have to check if the given statement is true.

Q: For a population with  = 15, a raw score of X = 82 corresponds to z = -0.60.  What is the mean for…

A: Consider that the mean and standard deviation of a random variable x are µ and σ, respectively.…

Q: Suppose that the blood pressure of the human inhabitants of a certain Pacific island is distributed…

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