The surface area of a game cube is 384 square millimeters. how long is each edge of the cube?

Don’t know how to solve.

iVinArrow [24]

Answer:

$122.88

Step-by-step explanation:

the phone decreases by 20% each year , that is

(100 - 20)% = 80% = $\frac{80}{100}$ = 0.8

the phone reduces by a factor of 0.8 each year , then after 4 years

value = $300 × $(0.8)^{4}$ = $122.88

3 0

2 years ago

A property has been assessed at $225 000. The mill rate is 14.5. To find the property tax, you would multiply the mill rate by:

jarptica [38.1K]

A would be the answer

8 0

3 years ago

A college infirmary conducted an experiment to determine the degree of relief provided by three cough remedies. Each cough remed

KiRa [710]

Answer:

$p_v = P(\chi^2_{4,0.05} >3.81)=0.43233$

Since the p values is higher than the significance level we FAIL to reject the null hypothesis at 5% of significance, and we can conclude that we don't have significant differences between the 3 remedies analyzed. So we can say that the 3 remedies ar approximately equally effective.

Step-by-step explanation:

A chi-square goodness of fit test "determines if a sample data matches a population".

A chi-square test for independence "compares two variables in a contingency table to see if they are related. In a more general sense, it tests to see whether distributions of categorical variables differ from each another".

Assume the following dataset:

NyQuil Robitussin Triaminic Total

No relief 11 13 9 33

Some relief 32 28 27 87

Total relief 7 9 14 30

Total 50 50 50 150

We need to conduct a chi square test in order to check the following hypothesis:

H0: There is no difference in the three remedies

H1: There is a difference in the three remedies

The level os significance assumed for this case is $\alpha=0.05$

The statistic to check the hypothesis is given by:

$\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}$

The table given represent the observed values, we just need to calculate the expected values with the following formula $E_i = \frac{total col * total row}{grand total}$

And the calculations are given by:

$E_{1} =\frac{50*33}{150}=11$

$E_{2} =\frac{50*33}{150}=11$

$E_{3} =\frac{50*33}{150}=11$

$E_{4} =\frac{50*87}{150}=29$

$E_{5} =\frac{50*87}{150}=29$

$E_{6} =\frac{50*87}{150}=29$

$E_{7} =\frac{50*30}{150}=10$

$E_{8} =\frac{50*30}{150}=10$

$E_{9} =\frac{50*30}{150}=10$

And the expected values are given by:

NyQuil Robitussin Triaminic Total

No relief 11 11 11 33

Some relief 29 29 29 87

Total relief 10 10 10 30

Total 50 50 50 150

And now we can calculate the statistic:

$\chi^2 = \frac{(11-11)^2}{11}+\frac{(13-11)^2}{11}+\frac{(9-11)^2}{11}+\frac{(32-29)^2}{29}+\frac{(28-29)^2}{29}+\frac{(27-29)^2}{29}+\frac{(7-10)^2}{10}+\frac{(9-10)^2}{10}+\frac{(14-10)^2}{10} =3.81$

Now we can calculate the degrees of freedom for the statistic given by:

$df=(rows-1)(cols-1)=(3-1)(3-1)=4$

And we can calculate the p value given by:

$p_v = P(\chi^2_{4,0.05} >3.81)=0.43233$

And we can find the p value using the following excel code:

"=1-CHISQ.DIST(3.81,4,TRUE)"

Since the p values is higher than the significance level we FAIL to reject the null hypothesis at 5% of significance, and we can conclude that we don't have significant differences between the 3 remedies analyzed.

4 0

3 years ago

The half-life of Radium-226 is 1590 years. If a sample contains 200 mg, how many mg will remain after 1000 years?

adell [148]

Answer: 129.33 g

Step-by-step explanation:

$$$Let $p=A \cdot e^{n t}$ \\$(p=$ present amount, $A=$ initial amount, $n=$ decay rate, $t=$ time)$

$\begin{aligned}&\Rightarrow \text { Given } p=\frac{A}{2} \ a t \ t=1590 \\&\Rightarrow \frac{1}{2}=e^{1590n} \Rightarrow n=\frac{\ln (1 / 2)}{1590}=-0.00043594162\end{aligned}$

$If $A=200 \mathrm{mg}$ and $t=1000$ then,$$\begin{aligned}P &=200 e^{\left(\frac{\ln \left(1/2\right)}{1590}\right) \cdot 1000} \text \\\\&=129.33 \text { grams}\end{aligned}$

3 0

2 years ago

. Three types of shirts sold at a store cost $9.00, $11.00, and $12.50. One day, the store sells a total of 23 shirts and makes

lbvjy [14]

Answer:

X + 3y = 23

9x + 36y = 243

11 shirts sold at $9.0 per shirt, 4 shirts sold at $11 per shirt and 8 shirts sold at $12.5 per shirt

Step-by-step explanation:

-----Since we are told to assume that the number of shirts sold for $9.00 each is x, that of $11.00 is y and also that of $12.50 is z.

9x + 11y + 12.5z = 243

9x + 11y + 12.5(2y) = 243

9x + 36y = 243_______ equation 1

----- The statement also read that One day, the store sells a total of 23 shirts and makes $243 on the sales. TWICE AS MANY SHIRTS WERE SOLD FOR $12.50 THAN WERE SOLD FOR $11.00

Z = 2y

x + y + z = 23

X + y + 2y = 23

X + 3y = 23_____ equation 2

Now multiply the above by 9 to have this equation's "x" sharing the same coefficient with that of equation 1

9x + 27 = 207 will be the new one___equation 3

-----Subtract equation 3 from 1 and we have

9x + 36y = 243____ equation 1

9x + 27y = 207____ equation 3

9y = 36

Y = 4

-----Substitute y = 4 in equation 2

X + 3y = 23

X + 4(3) = 23

X + 12 = 23

X = 23 - 12

X = 11

-----Remember that x + y + z = 23

11 + 4 + z = 23

15 + z = 23

Z = 23 - 15

Z = 8.

So therefore, x =11 shirts, y = 4 shirts and z = 8 shirts

4 0

3 years ago