Please Help!!! 10 Points! Brainliest answer

Sam takes part in a car race that has 20 laps. He completes 4 laps every 3 minutes. The number of laps Sam has left to drive aft

Nadya [2.5K]

If we rewrite this equation, it would look like this: $y=- \frac{4}{3}x+20$ , which is the equation for a straight line with a slope of -4/3 and a y-intercept of 20. The y-intercept exists when x = 0. "x" represents the number of minutes he drives, "y" represents the number of laps he drives. Slope is rise/run, or y/x, which gives us that he drives 4 laps in 3 minutes (the slope of our line). The y-intercept, when x = 0, tells us that when he has driven 0 minutes, or hasn't driven at all yet, he still has 20 laps to go. When y = 0, the x-intercept is $0=- \frac{4}{3}x+20$ , and $-20=- \frac{4}{3} x$ . Multiply both sides by 3 to get that -60 = -4x and that means that x is 15. This means that from start to finish, it takes him 15 minutes to drive the 20 laps.

4 0

3 years ago

Can you pls solve this

Neporo4naja [7]

Answer:

Me and my brother worked on this and now we got it.

Step-by-step explanation:

(4)

(9) (7)

(6) (5) (8)

7 0

4 years ago

Lie detectors Refer to Exercise 82. Let Y = the number of people who the lie detector says are telling the truth.

mr_godi [17]

Answer:

a) $P(Y\geq 10) = PX \leq 2) = 0.558$

b) $E(X) = \mu_X = np = 12*0.2 = 2.4$

$\sigma_X = \sqrt{np(1-p)}=\sqrt{12*0.2*(1-0.2)}=1.386$

$E(Y) = \mu_Y = np = 12*0.8 = 9.6$

$\sigma_Y = \sqrt{np(1-p)}=\sqrt{12*0.8*(1-0.8)}=1.386$

For this case the expected value of people lying is 2.4 and the complement is 9.6 and that makes sense since we have a total of 12 poeple.

And the deviation for both variables are the same.

Step-by-step explanation:

Assuming this previous info : "A federal report finds that lie detector tests given to truthful persons have probability about 0.2 of suggesting that the person is deceptive. A company asks 12 job applicants about thefts from previous employers, using a lie detector to assess their truthfulness. Suppose that all 12 answer truthfully. Let X = the number of people who the lie detector says are being deceptive"

For this case the distribution of X is binomial $X \sim N(n=12, p=0.2)And we define the new random variable Y="the number of people who the lie detector says are telling the truth" so as we can see y is the oppose of the random variable X, and the distribution for Y would be given by:[tex] Y \sim Bin (n=12,p=1-0.2=0.8)$

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

Part a

For this case we want to find this probability:

$P(Y \geq 10) = P(Y=10)+P(Y=11) +P(Y=12)$

And if we find the individual probabilites we got:

$P(Y=10)=(12C10)(0.8)^{10} (1-0.8)^{12-10}=0.283$

$P(Y=11)=(12C11)(0.8)^{11} (1-0.8)^{12-11}=0.206$

$P(Y=12)=(12C12)(0.8)^{12} (1-0.8)^{12-12}=0.069$

And if we replace we got:

$P(Y \geq 10) =0.283+0.206+0.069=0.558$

And for this case if we find $P(X\leq 2)=P(X=0) +P(X=1)+P(X=2)$ for the individual probabilites we got:

$P(X=0)=(12C0)(0.2)^0 (1-0.2)^{12-0}=0.069$

$P(X=1)=(12C1)(0.2)^1 (1-0.2)^{12-1}=0.206$

$P(X=2)=(12C2)(0.2)^2 (1-0.2)^{12-2}=0.283$

$P(X\leq 2)=0.283+0.206+0.069=0.558$

So as we can see we have $P(Y\geq 10) = P(X \leq 2) = 0.558$

Part b

Random variable X

For this case the expected value is given by:

$E(X) = \mu_X = np = 12*0.2 = 2.4$

And the deviation is given by:

$\sigma_X = \sqrt{np(1-p)}=\sqrt{12*0.2*(1-0.2)}=1.386$

Random variable Y

For this case the expected value is given by:

$E(Y) = \mu_Y = np = 12*0.8 = 9.6$

And the deviation is given by:

$\sigma_Y = \sqrt{np(1-p)}=\sqrt{12*0.8*(1-0.8)}=1.386$

For this case the expected value of people lying is 2.4 and the complement is 9.6 and that makes sense since we have a total of 12 poeple.

And the deviation for both variables are the same.

8 0

3 years ago

A typist can type 1800 words in 1 hour.Find the number of words that he can type per minute

Georgia [21]

Answer:

1800 words = 1 hour

1800 words = 60 minutes

Divide by 60: 30 words per minute.

Let me know if this helps!

6 0

3 years ago

Read 2 more answers

Which rule describes the x-coordinates in the translation below?.

Furkat [3]

Answer:

A) x + 0

Step-by-step explanation:

In triangle ABC, the coordinates are: A(1, -1), B(1, -5) and C(4, -5)

In triangle A'B'C', the coordinates are: A(1, -5), B(1, 1) and C(4, 1)

Look at the x-coordinates in both the triangles remains the same because the triangles are reflected over x-axis, therefore, only the y-coordinate changes.

Therefore, the rule for x-coordinates = x + 0

Answer: A) x + 0

Hope this was helpful.

Thank you.

6 0

3 years ago