Subtract the following. Write your answer in standard notation . 18-9.2×10^-4

A rectangular carpet has a perimeter of 244 inches. The length of the carpet is 90 inches more than the width. Determine the dim

RSB [31]

Answer:

The dimensions of rectangle are:

Width = 16 inches

Length = 106 inches

Step-by-step explanation:

Perimeter of rectangle = 244 inches

Let Width of rectangle = w

Length of rectangle = w+90

We need to find the dimensions (length and width) of the carpet

The formula used will be: $Perimeter=2(length+width)$

Putting values and making equation:

$244=2w+2(w+90)\\Solving:\\244=2w+2w+180\\244=4w+180\\Switching\:sides\\4w+180=244\\Subtracting\:180\:from\:both\:sides\\4w=244-180\\4w=64\\Dividing\:both\:sides\:by\:4\\\frac{4w}{4} =\frac{64}{4}\\w=16$

So, we get w = 16

The width w = 16 inches

Now, finding length = w+ 90 = 16+90 = 106 inches

Therefore the dimensions of rectangle are:

Width = 16 inches

Length = 106 inches

4 0

3 years ago

It is known that the life of a particular auto transmission follows a normal distribution with mean 72,000 miles and standard de

scoray [572]

Answer:

a) $P(X$

$P(z$

b) $P(X>65000)=P(\frac{X-\mu}{\sigma}>\frac{65000-\mu}{\sigma})=P(Z>\frac{65000-72000}{12000})=P(z>-0.583)$

$P(z>-0.583)=1-P(Z$

c) $P(X>100000)=P(\frac{X-\mu}{\sigma}>\frac{100000-\mu}{\sigma})=P(Z>\frac{100000-72000}{12000})=P(z>2.33)$

$P(z>2.33)=1-P(Z$

Sicne this probability just represent 1% of the data we can consider this value as unusual.

d) $z=1.28$

And if we solve for a we got

$a=72000 +1.28*12000=87360$

So the value of height that separates the bottom 90% of data from the top 10% is 87360.

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Part a

Let X the random variable that represent the life of a particular auto transmission of a population, and for this case we know the distribution for X is given by:

$X \sim N(72000,12000)$

Where $\mu=72000$ and $\sigma=12000$

We are interested on this probability

$P(X$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X$

And we can find this probability using excel or the normal standard table and we got:

$P(z$

Part b

$P(X>65000)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>65000)=P(\frac{X-\mu}{\sigma}>\frac{65000-\mu}{\sigma})=P(Z>\frac{65000-72000}{12000})=P(z>-0.583)$

And we can find this probability using the complement rule and excel or the normal standard table and we got:

$P(z>-0.583)=1-P(Z$

Part c

$P(X>100000)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>100000)=P(\frac{X-\mu}{\sigma}>\frac{100000-\mu}{\sigma})=P(Z>\frac{100000-72000}{12000})=P(z>2.33)$

And we can find this probability using the complement rule and excel or the normal standard table and we got:

$P(z>2.33)=1-P(Z$

Sicne this probability just represent 1% of the data we can consider this value as unusual.

Part d

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.1$ (a)

$P(X$ (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.

As we can see on the figure attached the z value that satisfy the condition with 0.9 of the area on the left and 0.1 of the area on the right it's z=1.28. On this case P(Z<1.28)=0.9 and P(z>1.28)=0.1

If we use condition (b) from previous we have this:

$P(X$

$P(z$

But we know which value of z satisfy the previous equation so then we can do this:

$z=1.28$

And if we solve for a we got

$a=72000 +1.28*12000=87360$

So the value of height that separates the bottom 90% of data from the top 10% is 87360.

5 0

3 years ago

does the following system of equations have a solution if so find it. 2x+y+z= 4 x-y+3z= -2 -x+y+z= -2

saul85 [17]

I'd suggest using "elimination by addition and subtraction" here, altho' there are other approaches (such as matrices, substitution, etc.).

Note that if you add the 3rd equation to the second, the x terms cancel out, and you are left with the system

- y + 3z = -2
y + z = -2
-----------------
4z = -4, so z = -1.

Next, multiply the 3rd equation by 2: You'll get -2x + 2y + 2z = -2.

Add this result to the first equation. The 2x terms will cancel, leaving you with the system

2y + 2z = -2
y + z = 4

This would be a good time to subst. -1 for z. We then get:

-2y - 2 = -2. Then y must be 0. y = 0.

Now subst. -1 for z and 0 for y in any of the original equations.

For example, x - (-1) + 3(0) = -2, so x + 1 = -2, or x = -3.

Then a tentative solution is (-3, -1, 0).

It's very important that you ensure that this satisfies all 3 of the originale quations.

5 0

4 years ago

The point P(5, −1) is rotated 90 degrees clockwise around the origin.

azamat

Answer:

C

Step-by-step explanation:

:)

3 0

2 years ago

Read 2 more answers

Help me please i don't know what i'm doing please help

UNO [17]

Answer: -1/9

Step by step explanation:

The common difference of an arithmetic sequence can be found by picking 2 consecutive terms, and subtracting the second from the first. For example, if I chose the terms 2 and 1 8/9, I would find the common difference by:

1 8/9 - 2, which is equal to -1/9.

You can confirm this by picking another pair of consecutive terms. Let's pick 1 7/9 and 1 2/3:

1 2/3 - 1 7/9 = -1/9, as 1 2/3 = 1 6/9, so 1 6/9 - 1 7/9 = -1/9

8 0

3 years ago