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kirza4 [7]
2 years ago
10

(CO 4) In a sample of 8 high school students, they spent an average of 24.8 hours each week doing sports with a sample standard

deviation of 3.2 hours. Find the 95% confidence interval, assuming the times are normally distributed.
(21.60, 28.00)

(22.12, 27.48)

(22.66, 26.94)

(24.10, 25.50)
Mathematics
1 answer:
AveGali [126]2 years ago
6 0

Answer:  

(22.12, 27.48)

Step-by-step explanation:

Given : Significance level : \alpha: 1-0.95=0.05

Sample size : n= 8 , which is a small sample (n<30), so we use t-test.

Critical values using t-distribution: t_{n-1,\alpha/2}=t_{7,0.025}=2.365

Sample mean : \overline{x}=24.8\text{ hours}

Standard deviation : \sigma=3.2\text{ hours}

The confidence interval for population means is given by :-

\overline{x}\pm t_{n-1,\alpha/2}\dfrac{\sigma}{\sqrt{n}}

i.e. 24.8\pm(2.365)\dfrac{3.2}{\sqrt{8}}

24.8\pm2.67569206001\\\\\approx24.8\pm2.68\\\\=(24.8-2.68, 24.8+2.68)=(22.12, 27.48)

Hence, the 95% confidence interval, assuming the times are normally distributed.=  (22.12, 27.48)

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Scrat [10]

Answer:

Ellen is correct

Step-by-step explanation:

Roger:

The left side 20 does not equal to the right side 0.002 , which means that the given statement is false.

Ellen:

The left side 20 is equal to the right side 20, which means that the given statement is always true.

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3 years ago
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Answer:

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Step-by-step explanation:

The amount of pizza is same as the area. The pizza is in a shape of a circle. The area of a circle is:

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Area of one medium size pizza is (diameter 25 means radius is 25/2 = 12.5):

A=\pi r^2\\A=\pi (12.5)^2\\A=490.87

So, area of two of these medium size pizzas is:

490.87 * 2 = 981.74

This should be the area of the large pizza. We can find the radius of that by substituting into formula. Shown below:

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you invested 1,000 in an account with interest rate at 2% compounded continuously. how long until 1400 is in your account?
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Answer:20 months

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Han recorded the number of pages that he read each day for five days. the dot plot shows his data. pages the mean, or average, f
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If the mean of the data set is 32.6. Then the number of pages he read in 5 days is 163.

<h3>What is Mean?</h3>

Mean is simply defined as the average of the given set of numbers. The mean is considered as one of the measures of central tendencies in statistics. The mean is said to be an arithmetic mean. It is the ratio of the sum of the observation to the total number of observations.

Han recorded the number of pages that he read each day for five days.

If the mean of the data set is 32.6 pages. Then the total number of the pages he read till now, will be

Let the total number of the pages be x. Then we have

\rm \dfrac{x}{5} = 32.6\\\\x  \ = 5 \times 32.6 \\\\x  \ = 163

More about the mean link is given below.

brainly.com/question/521501

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Answer:

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Step-by-step explanation:

The equation of a quadratic function in vertex form is

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a = 2

y = 2(x - 1)² + 1 ← in vertex form

5 0
3 years ago
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