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2 years ago

Ele:

Mathematics

1 answer:

lana66690 [7]2 years ago

5 0

Answer:

The pattern is that, every time a 9 is added. This pattern continuous forever.

Step-by-step explanation:

9 X 1 = 9

9 X 2 = 18 (9+9)

9 X 3 = 27 (9+9+9)

Etc.

You might be interested in

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard devia

Arturiano [62]

Answer:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

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)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

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 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

The margin of error is given by this formula:

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

And on this case we have that ME =+5 and we are interested in order to find the value of n, if we solve n from equation (2) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

4 0

3 years ago

Y=6x-11<br> -2x-3y=-7 gnjjj

KiRa [710]

Answer:

x=2 y=1

Step-by-step explanation:

Solve the equations by substituting y=6x-11 into -2x-3y=-7.

-2x-3(6x-11)=-7

-2x-18x+33=-7

-20x+33=-7

-20x=-7-33

-20x=-40

x=2

To find y, substitute this value into the equation and solve for y.

y=6(2)-11

y=12-11

y=1

7 0

2 years ago

Consider the following hypothesis test:H0: 20Ha: < 20A sample of 60 provided a sample mean of 19.6. The population standard d

elixir [45]

Answer:

a: z = -1.936

b: 0.0265

d: z < -1.645

Reject H0 if z < -1.645

Step-by-step explanation:

We are given:

H0: µ = 20

HA: µ < 20

n = 60, sample mean: 19.6, σ = 1.6

Since the alternate hypothesis has a < sign in it, it is a left tailed test. The < or > sign in the alternate hypothesis points towards the rejection region.

For a: We need to calculate the test statistic for our situation. This is done with a z-score formula for samples.

For b: we need to use the z-score table to look up the p-value for the score we calculate in part a. The p-value is 0.0265. This means that there is only about a 2.65% chance that the sample values were a result of random chance.

For d: Since the significance level is 0.05, and this is a one tailed test, we have a critical value of z < - 1.645. This means that if the z-score we calculate in part a is less than -1.645, we will reject the null hypothesis

See attached photo for all the calculations!

4 0

2 years ago

What ratio is represented in the table ?

dezoksy [38]

1. The tables represent a ratio of 3:5. For example, 6 x 3 = 18, and 6 x 5 = 30. Also, 20 x 3 = 60, and 20 x 5 = 100.
2. The table has a ratio of 3:4, so the missing blank is 64.

7 0

3 years ago

Read 2 more answers

The financial statements of the Tyler Company report net sales of $300,000 and accounts receivable of $50,000 and $10,000 at the

iragen [17]

Answer:

the accounts receivable turnover for the Tyler Company is 10

Step-by-step explanation:

The company report :

net sales = $300,000

account receivable = $50,000 and $10,000

to find the accounts receivable turnover, use the following formula:

accounts receivable turnover = net sales : average account receivable

First, we need to calculate the average account receivable of the company

average accounts receivable = ($50,000+$10,000) : 2

= $60,000 : 2

= $30,000

Then, substitute net sales into the formula

accounts receivable turnover = $300,000 : $30,000

= 10

4 0

2 years ago