The Hundred Years War led to the end of the Middle Ages in the beginning of the

Suppose that the sample standard deviation was s = 5.1. Compute a 98% confidence interval for μ, the mean time spent volunteerin

NISA [10]

Answer:

The 95% confidence interval would be given by (5.139;5.861)

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

2) Confidence interval

Assuming that $\bar X =5.5$ and the ranfom sample n=1086.

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=1086-1=1085$

Since the Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.01,1085)".And we see that $t_{\alpha/2}=2.33$

Now we have everything in order to replace into formula (1):

$5.5-2.33\frac{5.1}{\sqrt{1086}}=5.139$

$5.5+2.333\frac{5.1}{\sqrt{1086}}=5.861$

So on this case the 95% confidence interval would be given by (5.139;5.861) We are 98% confident that the mean time spent volunteering for the population of parents of school-aged children is between these two values.

5 0

3 years ago

Need help with all them plz and thank you and may god bless you

Elena-2011 [213]

1) Flounder
2) The second option(its blurry)
3) 4
4) 1
5) I think 52(its blurry)
6) 12
7) 2 1/3
8) 51
9) 5/6
10) 38
11) 40
12) The error is the negative sign because when finding absolute value the answer can never be zero since absolute value is the how far the thing is from zero, unless the negative sign is outside the absolute value lines.
13) >
14) =
15) <
16) >
17) a: your boat (18) friends boat (23).
b: your friends boat is farther behind the winning boat.
18) -2, 0, 1, 3, 5
19) -5, -3, 1, 3, 5
20) Always True
21) Never True
22) Sometimes

P.S You should give more points for this and you should get tutoring or you won't learn how to do this its pretty easy just a suggestion not calling you dumb or anything.

4 0

3 years ago

Hey I need help with 2+2

bulgar [2K]

Answer:

4

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

Please find mA and mB please.

Nikitich [7]