What percent of 6y is 24?

Can someone help me please

Scorpion4ik [409]

Answer:

B

Step-by-step explanation:

sohcahtoa

sin = opp/hyp

sin A = 16/20= 4/5

3 0

3 years ago

A university claims that the average cost of books per student, per semester is $300. A group of students believes that the actu

LenKa [72]

Answer:

$t=\frac{345-300}{\frac{200}{\sqrt{100}}}=2.25$

$p_v =P(t_{(99)}>2.25)=0.0133$

Conclusion

If we compare the p value and the significance level assumed $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the mean is higher than 300 at 1% of significance.

Step-by-step explanation:

Data given and notation

$\bar X=345$ represent the sample mean

$s=200$ represent the sample standard deviation

$n=100$ sample size

$\mu_o =300$ represent the value that we want to test

$\alpha$ 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 mean is higher than 300, the system of hypothesis would be:

Null hypothesis: $\mu \leq 300$

Alternative hypothesis: $\mu > 300$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

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

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

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

$t=\frac{345-300}{\frac{200}{\sqrt{100}}}=2.25$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=100-1=99$

Since is a one right tailed test the p value would be:

$p_v =P(t_{(99)}>2.25)=0.0133$

Conclusion

If we compare the p value and the significance level assumed $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the mean is higher than 300 at 1% of significance.

7 0

3 years ago

How to do both 14) and 16) b/c I have no idea. It is solving rational equations.

Vinvika [58]

Just like at any other time, to add/subtract fractions you need a common denominator.

14)

1/(x^2+2x)+(x-1)/x=1 so we need a common denominator of x(x^2+2x)

[1(x)]/(x(x^2+2x))+[(x-1)(x^2+2x)]/(x(x^2+2x))=[1(x(x^2+2x))]/(x(x^2+2x))

now if you multiply both sides of the equation by x(x^2+2x) you are left with:

x+(x-1)(x^2+2x)=x(x^2+2x)

x+x^3+2x^2-x^2-2x=x^3+2x^2

x^3+x^2-x=x^3-2x^2

x^2-x=-2x^2

3x^2-x=0

x(3x-1)=0, x=0 is an extraneous solution as division by zero is undefined. So the only real solution is:

x=1/3

...

16)

(r+5)/(r^2-2r)-1=1/(r^2-2r) the common denominator we need r^2-2r so

[r+5-1(r^2-2r)]/(r^2-2r)=1/(r^2-2r), multiplying both sides by r^2-2r yields:

r+5-r^2+2r=1

-r^2+3r+5=1

-r^2+3r+4=0

r^2-3r-4=0

(r-4)(r+1)=0, r^2-2r cannot equal zero, r(r-2)=0, r cannot equal 0 or 2...

r=-1 or 4

8 0

3 years ago

The ratio of girls to boy in the junior high band is 5 to 7. At the beginning of the year, there were 72 students in the band. B

kvasek [131]

I don't really understand this question do u have a pic?

5 0

3 years ago

Add and subtract fractions and mixed numbers<br><img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B5%7D%7B16%7D%20%20-%20%20%5Cfrac%

jasenka [17]

So we need a common denominator, and we'll choose 16 since that is common to both terms. What we do to the bottom of a fraction, we must also do to the top of the fraction, so in order to transform the fraction, we must do the following:

$\frac{1}{8}*\frac{2}{2}=\frac{2}{16}$

Now that we have this fraction with the correct denominator, we can subtract and solve the equation:

$\frac{5}{16} -\frac{2}{16} =\frac{3}{16}$

Since $\frac{3}{16}$ cannot be reduced any further, we are going to leave this as the answer.

So now we now that the answer is $\frac{3}{16}$ .

8 0

3 years ago