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3 years ago

Four streets feed into a roundabout circle as shown below. If the diameter of the

Mathematics

1 answer:

Natasha2012 [34]3 years ago

5 0

Answer: 119.1ft............

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You are standing 40 meters from the base of a tree that leans 8o away from you. The angle of elevation from you to the top of th

Y_Kistochka [10]

Answer:

the height of the tree is 15.49 m

Step-by-step explanation:

Step 1:

From the figure, we can determine ∠ATB by using the fact that the sum of all the angles in a triangle add up to 180°:

∠ ATB = 180° - 98° - 20°

∠ ATB = 62°

Step 2:

Therefore, using the law of sines, we can determine the height of the tree.

TB / sin(20°) = 40 / sin(62°)

TB = 40 × (sin(20°) / sin(62°))

TB = 15.49 m

Therefore, the height of the tree is 15.49 m

3 0

3 years ago

the marks in an examination for a Physics paper have normal distribution with mean μ and variance σ2 . 10% of the students obtai

Blababa [14]

Let $X$ be the random variable for the number of marks a given student receives on the exam.

10% of students obtain more than 75 marks, so

$P(X>75)=P\left(\dfrac{X-\mu}\sigma>\dfrac{75-\mu}\sigma\right)=P(Z>z_1)=0.10$

where $Z$ follows a standard normal distribution. The critical value for an upper-tail probability of 10% is

$P(Z>z_1)=1-F_Z(z_1)=0.10\implies z_1=F_Z^{-1}(0.90)$

where $F_Z(z)=P(Z\le z)$ denotes the CDF of $Z$ , and $F_Z^{-1}$ denotes the inverse CDF. We have

$z_1=F_Z^{-1}(0.90)\approx1.2816$

Similarly, because 20% of students obtain less than 40 marks, we have

$P(X$

so that

$P(Z$

Then $\mu,\sigma$ are such that

$\dfrac{75-\mu}\sigma\approx1.2816\implies75\approx\mu+1.2816\sigma$

$\dfrac{40-\mu}\sigma\approx-0.8416\implies40\approx\mu-0.8416\sigma$

and we find

$\mu\approx53.8739,\sigma\approx16.4848$

3 0

3 years ago

Evaluate 5c+cd when c=1/5 and d=15

oee [108]

5*1/5+1/5*15=4
1 + 3 =4

This should equal 4 if I did this correctly.

4 0

3 years ago

In a laboratory, they were testing a certain bacteria. They stated with 50 bacteria and they noticed it triples every 30 minutes

MaRussiya [10]

I think it’s just 4(50•3)=600

4 0

2 years ago

What is the answer 6v(2v + 3)

Firlakuza [10]

See attached picture

Hope this helps

6 0

3 years ago

Read 2 more answers