Can someone help me please

No idea how to do this equation. Its applying system's of linear equations.

icang [17]

What you want to do is take one of the 2 equations and isolate one variable. you will then use the value that you find for the variable and plug it back into the other equation. here is how:

This would be easiest to do with the second equation in the set since the x is not being multiplied by anything. So lets isolate the x in the second equation.

add 0.9y to both sides and you get:

x=4.5+0.9y

we now know what x is equal to in terms of y. so lets replace the x in the first equation with the new value. You get:

1.5(4.5+0.9y)-1.9y=-29

Now just solve for y:
6.75+1.35y-1.9y=-29
1.35y-1.9y=-35.75
-0.55y=-35.75
y=65

so now you know that y=65 so plug 65 in as y in the second equation to find x

x-0.9*65=4.5

Now simply solve for x

x-(-58.5)=4.5
x+58.5=4.5
x=-54

Hope this helped! :)

3 0

3 years ago

According to 2013 report from Population Reference Bureau, the mean travel time to work of workers ages 16 and older who did not

gregori [183]

Answer:

a) 48.80% probability that his travel time to work is less than 30 minutes

b) The mean is 30.7 minutes and the standard deviation is of 3.83 minutes.

c) 13.13% probability that in a random sample of 36 NJ workers commuting to work, the mean travel time to work is above 35 minutes

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question, we have that:

$\mu = 30.7, \sigma = 23$

a. If a worker is selected at random, what is the probability that his travel time to work is less than 30 minutes?

This is the pvlaue of Z when X = 30. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{30 - 30.7}{23}$

$Z = -0.03$

$Z = -0.03$ has a pvalue of 0.4880.

48.80% probability that his travel time to work is less than 30 minutes

b. Specify the mean and the standard deviation of the sampling distribution of the sample means, for samples of size 36.

$n = 36$

Applying the Central Limit Theorem, the mean is 30.7 minutes and the standard deviation is $s = \frac{23}{\sqrt{36}} = 3.83$

c. What is the probability that in a random sample of 36 NJ workers commuting to work, the mean travel time to work is above 35 minutes?

This is 1 subtracted by the pvalue of Z when X = 35. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{35 - 30.7}{3.83}$

$Z = 1.12$

$Z = 1.12$ has a pvalue of 0.8687

1 - 0.8687 = 0.1313

13.13% probability that in a random sample of 36 NJ workers commuting to work, the mean travel time to work is above 35 minutes

8 0

3 years ago

Player 1

sveta [45]

Answer:

Player 1's position is Player 2's position reflected across the y-axis; only the signs of the y-coordinates of Player 1 and Player 2 are different

Step-by-step explanation:

7 0

3 years ago

1.Which statement about two negative numbers is true? .

Ugo [173]

Answer:

To negative numbers makes a positive number.

(only in dividing and multiplying)

Step-by-step explanation:

Please mark me brainliest

3 0

3 years ago

Read 2 more answers

Solve the equation for x, where x is a real number (5 points): <br> -2x^2 + 5x - 10 = 3

KatRina [158]

Subtract 3 from both sides so that the equation becomes -2x^2 + 5x - 13 = 0.
To find the solutions to this equation, we can apply the quadratic formula. This quadratic formula solves equations of the form ax^2 + bx + c = 0
                                      x = [ -b ± √(b^2 - 4ac) ] / (2a)
                                      x = [ -5 ± √((5)^2 - 4(-2)(-13)) ] / ( 2(-2) )
                                      x = [-5 ± √(25 - (104) ) ] / ( -4 )
                                      x = [-5 ± √(-79) ] / ( -4)
Since √-79 is nonreal, the answer to this question is that there are no real solutions.

3 0

3 years ago