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3 years ago

Please help me !!!!!!

Mathematics

1 answer:

yawa3891 [41]3 years ago

7 0

Answer:

First answer is....

8(y-9)

Second answer is.....

Here,x^3=(5)^3=(5×5×5)=125

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Use the linear regression feature on a graphing calculator to find the correlation coefficient for the data. Round your answer t

Lerok [7]

Answer:

0.9769

Step-by-step explanation:

Given the data :

X : 7.5, 9.9, 4.8, 9, 8.1, 1.7, 3.1

Y : 35, 6, 45, 18, 20, 89, 84

The Correlation Coefficient obtained by using a graphing calculator to model the data above is : 0.9769, this means a strong positive correlation exists between the two variables.

7 0

3 years ago

The expression below represents the perimeter of a square in centimeters.

Aleks [24]

Answer:

Step-by-step explanation:

4(8.5) = 34

8 0

2 years ago

BRAINLIEST

Deffense [45]

Answer:

12.56 cubic inches

Step-by-step explanation:

V= π r^2 h/3

V= 3.14(2^2)(3/3)

V=3.14(4)(1)

V= 12.56

7 0

3 years ago

A rule for nth term of -2 , -5/4 ,-1/2,1/4

miv72 [106K]

Answer:

Step-by-step explanation:

This is an arithmetic sequence

a1 = -2

Difference = 2nd term - first term

$=\frac{-5}{4}-[-2]\\\\=\frac{-5}{4}+2\\\\=\frac{-5}{4}+\frac{2*4}{1*4}\\\\=\frac{-5+8}{4}=\frac{3}{4}$

$a_{n}=a+(n-1)d\\\\=-2+(n-1)*(\frac{3}{4})\\\\=-2+\frac{3}{4}n-\frac{3}{4}\\\\=\frac{-2*4}{1*4}-\frac{3}{4}+\frac{3}{4}n\\\\=\frac{-8-3}{4}+\frac{3}{4}n\\\\=\frac{-11}{4}+\frac{3}{4}n$

6 0

4 years ago

Examine the required sample size needed to be able to

Xelga [282]

Answer:

$n=(\frac{2.33(500)}{10})^2 =13572.25 \approx 13573$

And if we use a sample level of n =2000 the margin of error would be higher as we can see here:

$ME=2.33\frac{500}{\sqrt{2000}}=26.05$

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".

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

$\mu$ population mean (variable of interest)

$\sigma=500$ represent the population standard deviation assumed

n represent the sample size (variable of interest)

Confidence =98% or 0.98

ME = 10 represent the margin of error desired

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 =10 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 98% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.01;0;1)", and we got $z_{\alpha/2}=2.33$ , replacing into formula (b) we got:

$n=(\frac{2.33(500)}{10})^2 =13572.25 \approx 13573$

So the answer for this case would be n=13573 rounded up to the nearest integer

And if we use a sample level of n =2000 the margin of error would be higher as we can see here:

$ME=2.33\frac{500}{\sqrt{2000}}=26.05$

3 0

4 years ago