All categories

3 years ago

What is 1 fifth of a clock?

2 answers:

6 0

2.4 hours or 2 hours and 24 minutes represents $\frac{1}{5}$ of a clock.

The easiest way to find this is to divide 12 by 5 since there are twelve hours on a clock.
I got the 24 minutes by multiplying 60(minutes there are in an hour) by .4 and got 24.

lbvjy [14]3 years ago

3 0

2.4 hours or 2 hours and 24 minutes Is 1 fifth of a clock

You might be interested in

Find the domain of the function.

bonufazy [111]

x + 6 >= 0

x >= -6

Choice B is the answer.

Do you know why?

8 0

3 years ago

Given: y" - 2y' = 6t + 5e^2t. Find the correct form to use for y_p if the equation is solved using Undetermined coefficients. Do

const2013 [10]

Answer:

$y_p=A+Bt+Ce^{2t}$

Step-by-step explanation:

Given: $y'' - 2y' = 6t + 5e^{2t}$ .

we need to find the correct form for $y_p$ if the equation is solve using undetermined coefficients.

A first order differential equation $\frac{\mathrm{d} y}{\mathrm{d} x}=f\left ( x,y \right )$ is said to be homogeneous if $f(tx,ty)=f(x,y)$ for all t.

Consider homogeneous equation $y''-2y'=0$

Let $y=e^{rt}$ be the solution .

We get $(r^2-2r)e^{rt}=0$

Since $e^{rt}\neq 0$ , $r^2-2r=0$ .

So, we get solution as $y_c=c_1+c_2e^{2t}$

As constant term and $e^{2t}$ are already in the R.H.S of equation

$y" - 2y' = 6t + 5e^{2t}$ , we can take $y_p$ as $y_p=A+Bt+Ce^{2t}$

6 0

3 years ago

(- 6x + 7) + (2x - 6) = - 4x + 1

inna [77]

Answer:

Step-by-step explanation:

-4x + 1 = -4x + 1

1 = 1

infinitely many solutions

7 0

3 years ago

What is the solution to the equation -√(15+x)=-3?

marin [14]

So, the negative would be divided out to make it 3, then square both sides to get rid of the square root and get 9, then subtract 15 and you get -6. <span />

7 0

3 years ago

Read 2 more answers

SAT scores are normed so that, in any year, the mean of the verbal or math test should be 500 and the standard deviation 100. as

vovangra [49]

Answer:

a) $P(X>625)=P(\frac{X-\mu}{\sigma}>\frac{625-\mu}{\sigma})=P(Z>\frac{625-500}{100})=P(Z>1.25)$

$P(Z>1.25)=1-P(Z$

b) $P(400$

$P(-1$

c) $z=-0.842$

And if we solve for a we got

$a=500 -0.842*100=415.8$

So the value of height that separates the bottom 20% of data from the top 80% is 415.8.

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 SAT scores of a population, and for this case we know the distribution for X is given by:

$X \sim N(500,100)$

Where $\mu=500$ and $\sigma=100$

We are interested on this probability

$P(X>625)$

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:

$P(X>625)=P(\frac{X-\mu}{\sigma}>\frac{625-\mu}{\sigma})=P(Z>\frac{625-500}{100})=P(Z>1.25)$

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

$P(Z>1.25)=1-P(Z$

Part b

We are interested on this probability

$P(400$

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:

$P(400$

And we can find this probability with this difference:

$P(-1$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(-1$

Part c

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

$P(X>a)=0.8$ (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 0.2 of the area on the left and 0.8 of the area on the right it's z=-0.842. On this case P(Z<-0.842)=0.2 and P(Z>-0.842)=0.8

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:

$z=-0.842$

And if we solve for a we got

$a=500 -0.842*100=415.8$

So the value of height that separates the bottom 20% of data from the top 80% is 415.8.

8 0

3 years ago