A nationwide survey in 1995 revealed that U.S. grade-school children spend an average of µ = 8.4 hours per week doing homework. The distribution is normal with σ = 3.2. Last year, a sample of n = 100 grade-school children was given the same survey. For this sample, the mean number of homework hours was 7.1. Has there been a significant change in the homework habits of grade-school children? Test with α = .05.

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A: given data claim : μ < 69.1n = 280x¯ = 68.9σ = 2.88

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A: Hey there! Thank you for posting the question. Since your question has more than 3 parts, we are…

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A: Given, A B C D E 15 21 22 10 6 18 13 19 14 11 9 20 24 21 15 16 17 21 13 8

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A: Solution: Before After d = Before - After  (d-d) (d-d)2 39.2 40 -0.8 -1.5 2.25 38.5 37.9 0.6…

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Q: The mean salary of federal government employees on the General Schedule is $59,593. The average…

A: Hello! As you have posted 2 different questions, we are answering the first question. In case you…

Q: (a) The mean height of all adult American males is 69 inches (5 ft 9 in). A researcher wonders if…

A: We have to find out hypothesis..

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A: L

Q: Exercise 7.15 introduces data on shoulder girth and height of a group of individuals. In the data…

A: Given: r=0.695 Sy=9.01 Sx=10.13 Y=173.14X=105.87

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Q: A nutritionist claims that the mean tuna consumption by a person is 3.1 pounds per year. A sample…

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Q: Define Nonlinear Least Squares Estimation of a regression function?

A: Given that, Nonlinear Least Squares: Non-linear least squares is the form of least squares analysis…

Q: Women are recommended to consume 1770 calories per day. You suspect that the average calorie intake…

A: For the given data Perform t test for one mean

Q: A random sample of 88 eighth grade​ students' scores on a national mathematics assessment test has…

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A: The mean = 57.8The standard deviation = S = 6The sample size [n] =51Use t-distribution.

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A:

Q: Researchers at a National Weather Center in the northeastern United States recorded the number of 90…

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Q: 1.4 Using the production data from the table, determine the standard deviation of Milky Way's weekly…

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Q: A nutritionist claims that the mean tuna consumption by a person is 3.6 pounds per year. A sample of…

A: Given, A nutritionist claims that the mean tuna consumption by a person is 3.6 pounds per year. A…

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A:

Q: A normal population has a mean of μ = 25 on a communication effectiveness scale. After receiving a…

A: From the provided information, Sample size (n) = 4 Level of significance (α) = 0.05

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Q: A drug to reduce fever was given to a random saple of 8 patients who suffered from high fever. The…

A:

Q: For healthy adults, the mean pH of arterial plasma (i.e., acidity of the blood) is 7.4. A new drug…

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Q: The​ least-squares regression equation is y=761.7x+13,208 where y is the median income and x is the…

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Q: Noise Levels in Hospitals In a hospital study, it was found that the standard deviation of the sound…

A: From the given information we conduct F test for equality of two standard deviation.