Ask question

Ask question

All categories

denis-greek [22]

2 years ago

10

Meneca bought a package of 435 party favors to give to the guests at her birthday party. She calculated that she could give 9 pa

rty favors to each guest. How many guests is she expecting?

2 answers:

Makovka662 [10]2 years ago

8 0

She is expecting approximately 48 guests

Paul [167]2 years ago

6 0

She is expecting 48 guests

You might be interested in

kherson [118]

Answer:

a=1 b=4 c=-5

Step-by-step explanation:

7 0

2 years ago

How to do this problem

insens350 [35]

Answer:

multiply 2 with the parenthesis

19-2m<7+8m-8

then you put a dot between -2 amd 3

Step-by-step explanation:

5 0

3 years ago

On Monday, you realize that a significant theft occurred between 6PM Friday and 8AM Monday. You have good video tape of the time

Sergeu [11.5K]

For this one, find out how many hour have passed per day with 6 pm Friday being where you start.

6 pm Friday- 6 pm Saturday =24

6 pm Saturday - 6 pm Sunday= 24

6 pm Sunday - 6 am Monday = 12 hours

6 am Monday until 8 am Monday= 2 hours

Now just add the amount of hours together

24+24+12+2= 62 hours

Now convert that to minutes.

There are 60 minutes in 1 hour. You multiply the amount of hours by 60 to get the minutes.

62 hours times 60 minutes in 1 hour

62*60= 3720.

So you will have a total of 3,720 minutes of tape to review.

8 0

3 years ago

Read 2 more answers

Nina can ride her bike 63,360 feet in 3,400 seconds, and Sophia can ride her bike 10 miles in 1 hour. What is Nina's rate in mil

blondinia [14]

Hello, the answer for your question is<span> 12.7.</span>

5 0

3 years ago

Read 2 more answers

GRE Test: The Graduate Record Examination (GRE) is a test required for admission to many US graduate schools. Student’s scores o

Zepler [3.9K]

Answer:

a) $\bar X=144.3$

b) The 95% confidence interval would be given by (138.846;149.754)

c) n=34

d) n=298

e) n=1190

Step-by-step explanation:

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".

We can calculate the sample mean with this formula:

$\bar X = \frac{\sum_{i=1}^n x_i}{n}$

$\bar X=144.3$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=8.8$ represent the population standard deviation

n=10 represent the sample size

a) Find a point estimate of the population mean

We can calculate the sample mean with this formula:

$\bar X = \frac{\sum_{i=1}^n x_i}{n}$

$\bar X=144.3$

b) Construct a 95% confidence interval for the true mean score for this population.

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

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

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 table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $t_{\alpha/2}=1.96$

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

$144.3-1.96\frac{8.8}{\sqrt{10}}=138.846$

$144.3+1.96\frac{8.8}{\sqrt{10}}=149.754$

So on this case the 95% confidence interval would be given by (138.846;149.754)

Part c

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =+20 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (5) we got:

$n=(\frac{1.960(8.8)}{3})^2 =33.05 \approx 34$

So the answer for this case would be n=34 rounded up to the nearest integer

Part d

$n=(\frac{1.960(8.8)}{1})^2 =297.493 \approx 298$

So the answer for this case would be n=298 rounded up to the nearest integer

Part e

$n=(\frac{1.960(8.8)}{0.5})^2 =1189.97 \approx 1190$

So the answer for this case would be n=1190 rounded up to the nearest integer

7 0

3 years ago