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3 years ago

Please help me I would really appreciate it

Mathematics

2 answers:

Temka [501]3 years ago

8 0

Cos = adjacent / hypotenuse

cos B = 4/5

B = cos^-1 (4/5)

B = 36.869897....

B = 36.87° (nearest hundredth)

Angle B = 36.87°.

Radda [10]3 years ago

7 0

Answer:

$\boxed{\textsf{ The measure of unknown angle is \textbf{ 37}$^{\circ}$.}}$

Step-by-step explanation:

A right angled triangle is given to us with the sides 3 and 4 . We need to find the value of unknown angle that is $\sf \angle ABC$ .

So , here the measure of hypotenuse is 5 units .

$\sf \implies Hypotenuse = 5 \ units .$

And the measure of base is 4 units .

$\sf\implies Base = 4 \ units .$

Let us take the unknown angle be $\theta$ . That is let us take ,

$\sf \implies \angle ABC =\theta$

So here we can use the trigonometric ratios of cosine . The cosine can be expressed as a ratio of base and hypotenuse of a right angled triangle . Here ∆ABC . So , cosine is ,

$\qquad\boxed{\boxed{\sf cos\theta =\dfrac{base}{hypotenuse}}}$

Put on the respective values ,

$\sf\implies cos\theta =\dfrac{base}{hypotenuse}\\\\\sf\implies cos\theta =\dfrac{4}{5}\\\\\sf\implies \theta =cos^{-1}\bigg(\dfrac{4}{5}\bigg) \\\\\sf\implies \boxed{\pink{\sf \theta = 37^{o} . }}$

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PLZZZZ HELP The Lakeview city council is considering two different plans to help reduce the amount of pollution in the city. Pla

sdas [7]

1. The two equations follow the slope-intercept form which y=mx + b. They have the same y-intercept which is equal to 900.

2. Suppose x= 10
Plan Alpha: y=-7x+900=-7(10)+900=830
Plan Foxtrot: y = -17x+900 = -17(10)+900=730

Between the 2 plans, the lower value is 730. Plan Foxtrot is better for reduction of pollution.

3. The city council should choose Plan Foxtrot because the reduction of pollution is much greater. Their goal would be reached faster if they go with faster reduction of pollution.

5 0

3 years ago

The probability of passing the math class of Professor Jones is 64%, the probability of passing Professor Smith's physics class

alexgriva [62]

Answer:

The probability of using one or the other is 36%

Step-by-step explanation:

For solving this problem it is easy if we see it in a ven diagram, for this first we are going to name the initial conditions with some variables:

Probability of passing Professor Jones math class = 64% =0,64

P(J) = 0.64

Probabiliry of passing Professor Smith's physics class = 32% =0.32

P(S) = 0.32

Probability of passing both is = 30% = 0.30

P(JnS) = 0.30 (Is is an intersection so it is in the middle of the ven diagram

We need to know which is the probability of pasing one or the other for this we need to take out the probability of passing both for this we have to add the probability of passing Professor Jones math class with the probabiliry of passing Professor Smith's physics class and substract the probability of passing both for each one:

P(JuS) = (P(J) - P(JnS)) + (P(S) - P(JnS)) = (0.64 - 0.30) + (0.32 - 0.30) = 0.34 + 0.02 = 0.36 = 36%

If you check the ven diagram you can see that if we add all what is in red we will have the probability of passing Professor Jones math class and if we add all what is in blue we wiill have the probability of passing Professor Smith's physics class, and if we add just what is in each corner we will get the same value that is the probabilty of passsing one or the other.

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3 years ago

A research group needs to determine a 90% confidence interval for the mean repair cost for all car insurance small claims. From

lutik1710 [3]

Answer:

a) $z = 1.645$

b) The should sample at least 293 small claims.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$ , which means that the answer of question a is z = 1.645.

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

(b) If the group wants their estimate to have a maximum error of $12, how many small claims should they sample?

They should sample at least n small claims, in which n is found when

$M = 12, \sigma = 124.88$ . So

$M = z*\frac{\sigma}{\sqrt{n}}$

$12 = 1.645*\frac{124.88}{\sqrt{n}}$

$12\sqrt{n} = 205.43$

$\sqrt{n} = \frac{205.43}{12}$

$\sqrt{n} = 17.12$

$\sqrt{n}^{2} = (17.12)^{2}$

$n = 293$

The should sample at least 293 small claims.

8 0

3 years ago

A county's population in 1991 was 147 million. In 1998 it was 153 million. Estimate the population in 2017 using the exponential

aliina [53]

Let t=number of years since 1991.
Then
P(t)=147 e^(kt) ... in millions
P(0)=147 e^(0)=147
P(7)=147 e^(7k)=153
e^(7k)=(153/147)
take ln both sides
ln(e^(7k))=ln(153/147)
7k=0.0400 => k=0.005715

Year 2017=>t=2017-1991=26
P(26)=147e^(26*.005715)=170.55
Answer: in 2017, the projected population is 170.55 millions.

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4 years ago

The perimeter of the square below is 36. What is the length of the diagonal, x? A.6 B.9 C.62–√ D.92–√

siniylev [52]

Answer:

9 $\sqrt{2}$

Step-by-step explanation: did it

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3 years ago