Plzz help will give Brainlest!!

Here are summary statistics for randomly selected weights of newborn girls: nequals=174174, x overbarxequals=30.930.9 hg, seq

MaRussiya [10]

Answer:

The 95% confidence interval would be given by (29.780;32.020)

Step-by-step explanation:

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".

$\bar X=30.9$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=7.5 represent the sample standard deviation

n=174 represent the sample size

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:

$df=n-1=174-1=173$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-T.INV(0.025,173)".And we see that $t_{\alpha/2}=1.97$ , this value is similar to the obtained with the normal standard distribution since the sample size is large to approximate the t distribution with the normal distribution.

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

$30.9-1.97\frac{7.5}{\sqrt{174}}=29.780$

$30.9+1.97\frac{7.5}{\sqrt{174}}=32.020$

So on this case the 95% confidence interval would be given by (29.780;32.020)

The value 29.6 is not contained on the interval calculated.

5 0

3 years ago

What is 1/4 times 48

svetlana [45]

Simplifiy the answer it'll become 2

8 0

3 years ago

Read 2 more answers

Selecting an SUV with a blue exterior

frozen [14]

The answer is straightforward, by the "rule of product":

There are

3×8×2=48

different combinations (distinct possible cars) that can be created.

There 33 choices for body style; 88 choices for exterior colors, and 22 choices of interior color schemes:

Since each of these choices are independent (the choice of body style doesn't depend on exterior or interior color, e.g.) we multiply the number of choices for each quality to obtain: 3×8×2=483×8×2=48 distinct ways to create a car

6 0

2 years ago

Find a whole number solution that makes the following true

slamgirl [31]

I don't think any of them exist. the only ones I can think of make my feel there are any others

3 0

3 years ago

Simplify 4+(-3)-2x(-6)

jonny [76]

Answer:

1 + 12

Step-by-step explanation:

Let's do this one step by step!

We are going to make sure that we pay attention to the part in the parenthesis first!

Let's multiply -2x with -6 first.

Equation:

4+(-3)-2x(-6)

We do not need to parenthesis around the -3 because a negative cancels out a positive. So, no matter what you would have to subtract.

4 - 3 + 12x

And we get a positive 12 because both numbers that were being multiplied were negative.

Now let's combine common terms.

1 + 12x

This is your answer! I hope this helped!

8 0

3 years ago