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4 years ago

Help with 5 and 6 please !! (13 points!!)

Mathematics

2 answers:

melamori03 [73]4 years ago

8 0

Hi i can help you but i do not understand your question

tangare [24]4 years ago

6 0

Your answer to 5 and 6 would both be here but you did not post a picture

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( BRAINLIEST QUEATION)

mr Goodwill [35]

Answer:

Step-by-step explanation:

Weight decreased = 108 - 88 = 20 Kg

Percentage decrease = $\frac{20}{108}*100$

= 18.52%

3 0

3 years ago

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

Given the graph below, find the slope. A. -3/2 B.3/2 C -2/3 D. 2/3

Irina18 [472]

The answer is or the slope is D 2/3

8 0

3 years ago

WILL GIVE BRIANLIEST

Wittaler [7]

Based on the graph, all x values are possible so the answer is C.

6 0

3 years ago

PLSSS? i dont really get it Thanks

solmaris [256]

Answer:

A) 83 km/ hour

B) 2/7 penalties / game

C) $16 / CD

D) 9 donuts / box

Step-by-step explanation:

For this question they are asking for the distance traveled in 1 hour.

Since 747km was travelled in 9 hours, we divide 747 by 9 to find the distance travelled in 1 hour

747 ÷ 9 = 83

The unit rate is 83 km/ hour

You have to find the number of penalties per game

Like before divide 10 by 35:

10 ÷ 35 = 10/35 = 2/7

2/7 penalties / game

Find the cost of 1 CD :

64 / 4 = 16

$16 / CD

Find the amount of donuts per box:

72/8 = 9

9 donuts per box

-Chetan K

3 0

3 years ago

Read 2 more answers