Solve. −6 1/4x=−3 1/8 What is the solution to the equation? Enter your answer as a simplified fraction in the box.

An instructor who taught two sections of Math 161A, the first with 20 students and the second with 30 students, gave a midterm e

uranmaximum [27]

Answer:

The answers are for option (a) 0.2070 (b)0.3798 (c) 0.3938

Step-by-step explanation:

Given:

Here Section 1 students = 20

Section 2 students = 30

Here there are 15 graded exam papers.

(a )Here Pr(10 are from second section) = ²⁰C₅ * ³⁰C₁₀/⁵⁰C₁₅= 0.2070

(b) Here if x is the number of students copies of section 2 out of 15 exam papers.

here the distribution is hyper-geometric one, where N = 50, K = 30 ; n = 15

Then,

Pr( x ≥ 10 ; 15; 30 ; 50) = 0.3798

(c) Here we have to find that at least 10 are from the same section that means if x ≥ 10 (at least 10 from section B) or x ≤ 5 (at least 10 from section 1)

so,

Pr(at least 10 of these are from the same section) = Pr(x ≤ 5 or x ≥ 10 ; 15 ; 30 ; 50) = Pr(x ≤ 5 ; 15 ; 30 ; 50) + Pr(x ≥ 10 ; 15 ; 30 ; 50) = 0.0140 + 0.3798 = 0.3938

Note : Here the given distribution is Hyper-geometric distribution

where f(x) = kCₓ)(N-K)C(n-x)/ NCK in that way all these above values can be calculated.

7 0

3 years ago

The mean life of a tire is 30,000 km. The standard deviation is 2000 km. 95% of all tires will have a life between___ km and ___

Llana [10]

Answer:Need more infromation

7 0

3 years ago

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If you are solving y 2+2y=48 by completing the square, the next line would be

snow_tiger [21]

For this case we have the following equation:

$y ^ 2 + 2y = 48$

By completing squares we have:

Step 1:

Add $(\frac {b} {2}) ^ 2$ on both sides:

$y ^ 2 + 2y + 1 = 48 + 1$

Step 2:

We rewrite the equation:

$(y + 1) ^ 2 = 49$

Step 3:

We solve the equation:

$y = \pm \sqrt {49} -1\\y = \pm7-1$

Solutions:

$y = 6\\y = -8$

Answer:

the next line would be:

$y ^ 2 + 2y + 1 = 48 + 1$

6 0

3 years ago

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Your question

Alex777 [14]

2x+4.7=77.8

double the unknown number then add 4.7

8 0

2 years ago

The Lees have 3 children. The oldest is twice as old as the youngest. The middle is 5 years older than the youngest. If the sum

valina [46]

Oldest = 2 times Youngest -> O = 2*Y
Middle = Youngest + 5 -> M = Y+5
All of them together is 57 -> O + M + Y = 57

So you have these three equations:
(1) O = 2*Y
(2) M = Y+5
(3) O + M + Y = 57

Now you want to reduce the number of variables. You can change the second equation to be Y = M-5 and then plug in "M-5" wherever there is currently a Y:

(4) O = 2*(M-5) = 2*M - 10
(5) O + M + (M-5) = 57
which becomes O + 2M = 62

Then you plug in the "O" equation (4) into (5) which gives you
(2M-10) + 2M = 62 which reduces to 4M = 72.

So now I know M is 18.
I can now plug that into my other equations:
(4) O = 2*18 - 10 which means O = 26.
Now I plug that into (1) from the top:
26 = 2*Y which becomes 13 = Y

So now I have O, Y, and M
Oldest is 26
Middle is 18
Youngest is 13

Reading the sentence again, you can see that this makes sense.

4 0

3 years ago

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