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2 years ago

Find the total area of the four walls of a room 12 m long, 10 m wide and 4 m high.

Mathematics

1 answer:

Radda [10]2 years ago

8 0

Answer:

Step-by-step explanation:

<h3>Area = Length * Width</h3><h3>Volume = Length * Width * Height</h3>

<h3>As we all can see,from the question we were given the parameters for calculating volume instead of the ones for calculating "area"</h3>

<h3>But from the the parameters, we can calculate for the total surface area</h3>

<h3>Floor = 12m ×10m = 120m^2</h3>

<h3>Front and back walls (x2) = 10m × 4m ×2 = 80m^2</h3>

<h3>Side walls (x2) = 12m × 4m × 2 = 96m^2</h3><h3>Total surface area</h3>

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A random sample of 49 measurements from one population had a sample mean of 15, with sample standard deviation 5. An independent

kotykmax [81]

Answer:

Comparing the p value with the significance level $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the difference between the two groups is significantly different.

Step-by-step explanation:

$\bar X_{1}=15$ represent the mean for sample 1

$\bar X_{2}=18$ represent the mean for sample 2

$s_{1}=5$ represent the sample standard deviation for 1

$s_{f}=6$ represent the sample standard deviation for 2

$n_{1}=49$ sample size for the group 2

$n_{2}=64$ sample size for the group 2

$\alpha=0.01$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the difference in the population means, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{2}=0$

Alternative hypothesis: $\mu_{1} - \mu_{2}\neq 0$

We don't have the population standard deviation's, so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}$ (1)

And the degrees of freedom are given by $df=n_1 +n_2 -2=49+64-2=111$

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

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

$t=\frac{(15-18)-0}{\sqrt{\frac{5^2}{49}+\frac{6^2}{64}}}}=-2.897$

P value

Since is a bilateral test the p value would be:

$p_v =2*P(t_{111}$

7 0

3 years ago

(repost cuz the last didn’t load) please help ‼️

shtirl [24]

1: (pi)5^2 = 78.54 then multiply that by 11 and you get 863.94
2: (pi)13^2= 530.93 then multiply that by 8 and you get 47247.44
3. (pi)18^2= 1017.88 then multiply that by 22 and you get 22393.36

8 0

3 years ago

In a class 3/4 of the boys like math, 1/2 like science, 1/4 of those who like science do not like math. How many boys like neith

wariber [46]

Brainiest Answer:
D.1/8

5 0

3 years ago

Henry spends $50.00 on lunch, $12.00 on a cap and spends $6.00 on bananas. Hicks spend $120.00 on clothes and $15 on a cap. Henr

velikii [3]

Answer: his lunch will cost him 45 dollar

Step-by-step explanation:

3 0

3 years ago

Please answer right away!!!

liraira [26]

Answer:

22.9m

Step-by-step explanation:

Using Pythagorean theorem, we can get two equations using the angles.

From Point A:

∠A = 20°

AB = 20m

From Point B:

∠B = 29°

BD = x

What we are looking for is the opposite side of each right triangle, each person makes because we have one adjacent side. We also know that both opposite sides will be equal.

So we use this formula for both point of views:

$Tan\theta=\dfrac{Opposite}{adjacent}$

Where:

Opposite = height of the building

Adjacent = distance from the building

We are looking for the opposite side so we can tweak our formula to get an equation for the height

$height=(Tan\theta)(distance)$

Using our given, we can solve for the distance of point B to D:

$(Tan20)(20+x) = (Tan29)(x)\\\\(0.3640)(20+x) = (0.5543)(x)\\\\\dfrac{(7.28+0.3640x)}{0.5543}=x\\\\13.1337 + 0.6567x = x\\\\13.1337 = x - 0.6567x\\\\13.1337 = 0.3433x\\\\\dfrac{13.1337}{0.3433}=x\\\\38.2572 = x$

The distance of point B to D is 38.2572 m.

Now that we know the distance of BD we can solve for the height of the building using only the given from point B.

$height=(Tan\theta)(distance)$

$height=(Tan29)(38.2572m)$

$height=(0.5543)(38.2572m)$

$height=21.21m$

But this is only the height from the line of sight. To get the height of the building from the ground, we just add the height of the viewer, which is 1.7m.

21.21m + 1.7m = 22.91m

The closest answer is: 22.91 m

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3 years ago