(01.03)

How do you find the surface area for this shape?

fgiga [73]

Answer:

total area is the total of the areas of each of the rectangular surfaces
67 units²

Step-by-step explanation:

Add up the surface areas of each of the 6 faces.

There are two top/bottom faces with the same area, two left/right faces with the same area, and two front/back faces with the same area. So you only need to figure the areas for 3 faces, then multiply that sum by 2. Of course the area of each rectangle is the product of its length and width. For length, width, and height dimensions L, W, and H, the total area is ...

A = 2(LW +WH +LH)

= 2(LW +H(L+W)) . . . . . I like this form because there's one less multiplication

= 2(5·4 + 1.5(5+4)) = 2(20 +13.5)

A = 67 . . . units²

_____

<em>Comment on dimensions</em>

It does not matter which number you use for length, width, or height. The problem is symmetrical that way, so any of the dimensions can be called any of those things. You need to use the same number consistently for height (for example) once you have made the choice of which is which.

3 0

3 years ago

A bag contains 4 red balls, 2 green balls, 3 yellow balls, and 5 blue balls. Find each probability for randomly removing balls w

AfilCa [17]

Answer:

$\frac{15}{4802}$ , $\frac{15}{9604}$ , $\frac{9}{2401}$ , $\frac{9}{4802}$

Step-by-step explanation:

The bag has a total of (4+2+3+5) = 14 balls. Set up the proportions:

Red: $\frac{4}{14}$

green: $\frac{2}{14}$

yellow: $\frac{3}{14}$

blue: $\frac{5}{14}$

Now solve!

Removing 1 yellow, 1 red, 1 green, and 1 blue = $\frac{3}{14} \cdot \frac{4}{14} \cdot \frac{2}{14} \cdot \frac{5}{14} =\frac{15}{4802}$

Removing 1 blue, 1 green, 1 green, and 1 yellow = $\frac{5}{14} \cdot \frac{2}{14} \cdot \frac{2}{14} \cdot \frac{3}{14} =\frac{15}{9604}$

Removing 1 red, 1 red, 1 yellow, and 1 yellow = $\frac{4}{14} \cdot \frac{4}{14} \cdot \frac{3}{14} \cdot \frac{3}{14} =\frac{9}{2401}$

Removing 1 green, 1 yellow, 1 yellow, and 1 red = $\frac{2}{14} \cdot \frac{3}{14} \cdot \frac{3}{14} \cdot \frac{4}{14} =\frac{9}{4802}$

4 0

2 years ago

I need help!!! please help me!!!

natta225 [31]

Answer:

um ok the laiyflylfug;ou;

Step-by-step explanation:

4 0

3 years ago

Evaluate: (5−5×8−10)−5

Brums [2.3K]

Answer:

-50

Step-by-step explanation:

6 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