Someone help pls, 3.12

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

PLEASE HELP WILL GIVE BRIANLIEST!

IceJOKER [234]

Answer:

A"(1, -5)

B"(3, -5)

C"(4, -3)

D"(2, -3)

Step-by-step explanation:

When you are graphing coordinates make sure you have graph paper. When you plot the coordinates you reflect it over the x axis. The slide down 2 units down.

Hope this helps ☝️☝☝

3 0

3 years ago

Three letters are chosen at random from the letters P, A, N, S, O, L. What is the size of the sample space of this experiment? A

AVprozaik [17]

You need to find the number of permutations of the 6 different letters, taken 3 at a time.
$6P3=\frac{6!}{(6-3)!}=\frac{6\times5\times4\times3\times2\times1}{3\times2\times1}=120$
Therefore the sample space is 120 possible outcomes.

3 0

3 years ago

Read 2 more answers

Which statements are true about the interquartile range? Select all that apply.

PilotLPTM [1.2K]

Answer:

The true statements are:

B. Interquartile ranges are not significantly impacted by outliers

C. Lower and upper quartiles are needed to find the interquartile range

E. The data values should be listed in order before trying to find the interquartile range

Step-by-step explanation:

The interquartile range is the difference between the first and third quartiles

Steps to find the interquartile range:

Put the numbers in order
Find the median Place parentheses around the numbers before and after the median
Find Q1 and Q3 which are the medians of the data before and after the median of all data
Subtract Q1 from Q3 to find the interquartile range

The interquartile range is not sensitive to outliers

Now let us find the true statements

A. Subtract the lowest and highest values to find the interquartile range ⇒ NOT true (because the interquartial range is the difference between the lower and upper quartiles)

B. Interquartile ranges are not significantly impacted by outliers ⇒ True (because it does not depends on the smallest and largest data)

C. Lower and upper quartiles are needed to find the interquartile range ⇒ True (because IQR = Q3 - Q2)

D. A small interquartile range means the data is spread far away from the median ⇒ NOT true (because a small interquartile means data is not spread far away from the median)

E. The data values should be listed in order before trying to find the interquartile range ⇒ True (because we can find the interquartial range by finding the values of the upper and lower quartiles)

4 0

3 years ago

Read 2 more answers

A basketball player made 75 baskets in a season. Of these, 8% were three-point shots. How many three-point shots did the player

ale4655 [162]

Answer:

6

Multiply 75 by .08, because that's 8% in decimal from.

6 0

3 years ago