For this item, enter the answer in the space provided.

saw5 [17]

So to solve for this, we need to set up proportional fractions, which I will help show you how to do.
First, if we are given an amount out of a total, we need to put it over x (if we are looking for the total). It looks like this:
12/x, 12 being the given number and x being the total.
If we are given the total but are looking for an amount, put the total at the bottom of the fraction (aka the denominator). It looks like this: x/16, 16 being the total amount and x being the amount out of the total.
We have a total of 40 test problems, so we can put our total at the bottom, x/40.
X is the amount of questions answered correctly (we are looking for x in the question).
We have answered 80% correct, so put 80% over 100 (100 being the total). It should look like this: 80/100.
Now we have our two fractions: x/40 & 80/100.
Set these up as an equation.
x/40 = 80/100.
Now this is where things may get tricky if you don't pay attention.
Multiply the numerator (the top number of a fraction) of x/40 by the denominator (the bottom number of a fraction) of 80/100.
Your product equation should look like this:
x times 100. This will give is 100x. Leave it at that.
Now, multiply the denominator of x/40 (the bottom number of the fraction) by the numerator (the top number of a fraction) of 80/100. It should look like this:
80 x 40. This will give us 3200.
Now set up our products as an equation.
100x = 3200.
To solve for x, divide both sides by 100.
3200/100 = 32.
x = 32.
I hope this helps and has taught you something!

4 0

3 years ago

How do I factor 2x^2 + 11x +5

ASHA 777 [7]

(2x+1)(x+5) is the answer.

4 0

3 years ago

How to solve this problem

Arisa [49]

First, you solve the square root:

$9+ \sqrt{-4}$

Knowing that the square root of a negative number doesn't exist:

$9+ \sqrt{-4}$
$9+2i$ is your answer.

Hope it helped,

Happy homework/ study/ exam!

4 0

3 years ago

Simplify simplify please help simplify

neonofarm [45]

Answer:

6<em>i</em> and -6<em>i</em>

Step-by-step explanation:

since its a negative then you have to remember to add a i

3 0

3 years ago

According to the Census Bureau, 3.39 people reside in the typical American household. A sample of 26 households in Arizona retir

Vikki [24]

Answer:

$t=\frac{2.73-3.39}{\frac{1.22}{\sqrt{26}}}=-2.758$

$df=n-1=26-1=25$

$p_v =P(t_{(25)}$

Since the p value is lower than the significance level 0.1 we have enough evidence to reject the null hypothesis, and we can conclude that the true mean is significanlty lower than 3.39 personas at 10% of significance.

Step-by-step explanation:

Data given and notation

$\bar X=2.73$ represent the sample mean

$s=1.22$ represent the sample standard deviation

$n=26$ sample size

$\mu_o =3.39$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is less than 3.39 persons, the system of hypothesis would be:

Null hypothesis: $\mu \geq 3.39$

Alternative hypothesis: $\mu < 3.39$

The statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{2.73-3.39}{\frac{1.22}{\sqrt{26}}}=-2.758$

P-value

The degreed of freedom are given by:

$df=n-1=26-1=25$

Since is a one sided lower test the p value would be:

$p_v =P(t_{(25)}$

Conclusion

Since the p value is lower than the significance level 0.1 we have enough evidence to reject the null hypothesis, and we can conclude that the true mean is significanlty lower than 3.39 personas at 10% of significance.

3 0

2 years ago