A correlation of 0.7 was found between time spent studying and percentage on an exam. What is the proportion of variance in exam scores that can be explained by time spent studying? A. 0.30 ©0.49 B. 0.40 D. 0.70

Q: In 1980 and again in 2010, a Gallup poll asked a random sample of 1000 US citizens "Are you in favor…

A:

Q: some reports, the mean and coefficient of variation are given. For instance, one report gives the…

A: Given that the mean is 2.6 and the coefficient of variation is 2.7%. We have to find the standard…

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A:

Q: I surveyed a sample of 68 customers in a business to see how much they spend in there.  Would this…

A: Parameter: Any statistical measure based on all units in the population is called Parameter.…

Q: the mean = 146, and s =  35 Question #3 A percentage of female students with scores between 41 and…

A: From the provided information, Mean (x̅) = 146 Standard deviation (s) = 35

Q: Two individuals a spatial abilities test (mean = 80, std. dev. = 8). One scores a 76 and the scores…

A: From the given information,

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Q: 1. (12pt) A researcher is studying hospital cleanliness comparing carpeted rooms with uncarpeted…

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A: Given Z=2.56

Q: What is the Z value for a value of X = 60?

A:

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Q: John calculated r -.44 for a set of n 10 pairs of values that represent the number of absences from…

A: Given that r = -0.44 midterm exam score ( y )   number of absences from class (x)

Q: Example 1: Recent research suggests that a pregnancy within less than two years of a live birth…

A: Given: Sample size n = 15 Significance level α = 0.10 Formula Used: Test-statistic t = d-μdsdn…

Q: For a set of 250 measurements the mean is 110 and the variance is 144, how many of these…

A: Mean = μ = 110 Variance σ2 = 144Standard deviation = σ = σ = 12

Q: Fimd the Z score associated with the 15th percentile.

A:

Q: A sample of n = 10 scores has a mean of M = 13. After one score is added to the sample, the mean is…

A: Solution-: Given: n=10,M=13 (old)We want to add one score in the sample, the mean is found to be M =…

Q: 1. (12pt) A researcher is studying hospital cleanliness comparing carpeted rooms with uncarpeted…

A:

Q: Suppose X ∼N (-4,1. Between what xx values does 99.72% of the data lie?

A: Given: X ∼N (-4,1 ) To find: Between what xx values does 99.72% of the data lie?

Q: IQ is normally distributed with a mean of 100 (SD = 15). What score would a person need to be in the…

A: Let X denote the IQ scores and it follows normal distribution with mean of 100 and standard…

Q: We want to do a comparison of cow's milk with plant-based milk as far as nutrition is concerned.…

A: From the provided information,

Q: Suppose a friend tells you that the average length of trout caught in pyramid lake is u=19 inches.…

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A: From the Excel function, 1st quartile 0.0825 =QUARTILE(D2:D31,1) 3rd quartile 0.23…

Q: Measure the significance of the difference in the height of Chris's friend before and now with a…

A:

Inverse Normal Distribution

The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.

Mean, Median, Mode

It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.

Z-Scores

A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.