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4 years ago

Danny is opening a savings account with an

Mathematics

1 answer:

Phoenix [80]4 years ago

8 0

Well the equation is y= 3x + 45. Your starting point is 45 because he started with depositing 45 bucks. The 3 represents how much he earns each day so it’s constant

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My brother wants to estimate the proportion of Canadians who own their house.What sample size should be obtained if he wants the

AVprozaik [17]

Answer:

a) $n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

b) $n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

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".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

If solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Part a

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ . And the critical value would be given by:

$z_{\alpha/2}=\pm 1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

Part b

For this case since we don't have a prior estimate we can use $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

8 0

3 years ago

Answer please ASAP!!!!!!

weqwewe [10]

<h3>Answer: 282.6 square units</h3>

====================================================

Work Shown:

r = 3 is the radius of the circular base

h = 12 is the height of the cylinder

pi = 3.14 approximately

SA = surface area of the cylinder

SA = 2pi*r^2 + 2pi*r*h

SA = 2*3.14*3^2 + 2*3.14*3*12

SA = 282.6

3 0

3 years ago

PLEASE HELPPPPPP EASY

lianna [129]

The answer to your question is D

5 0

2 years ago

ABM Services paid a $4.15 annual dividend on a day it closed at a price of $54 per share. What

Leni [432]

Answer:

- 22719559.

Step-by-step explanation:

3 0

3 years ago

Factorise fully x^3-x

MA_775_DIABLO [31]

Answer:

$x(x+1)(x-1)$

Step-by-step explanation:

We see that the two terms share an x, so we can pull that out:

$x^3-x=x(x^2-1)$

Now notice that we have a difference of squares ( $x^2-1$ ). Given a difference of squares, $a^2-b^2$ , this can always be factored into $(a+b)(a-b)$ . We can use this in this case: $x^2-1=(x+1)(x-1)$ .

So, our final factorized form is: $x(x+1)(x-1)$ .

Hope this helps!

3 0

3 years ago