Ask question

Ask question

All categories

3 years ago

14

Abhasra spent half of her week let allowance at the movies. to earn more money her parents let her clean the windows in the hous

e for 7 dollars. what is her weekly allowance is she ended with 12

1 answer:

lutik1710 [3]3 years ago

5 0

Answer:

the answer is 16

Step-by-step explanation:

You might be interested in

(x+7)^2+9=0<br><br> Find x with quadratics

Ne4ueva [31]

Answer:

x = -7 ±3i

Step-by-step explanation:

(x+7)^2+9=0

Subtract 9 from each side

(x+7)^2+9-9=0-9

(x+7)^2=-9

Take the square root of each side

sqrt((x+7)^2) = ±sqrt(-9)

We know sqrt(ab) = sqrt(a) sqrt(b)

x+7 = ±sqrt(-1) sqrt(9)

We know that sqrt(-1) is the imaginary number i

x+7 = ±i *3

x+7 =±3i

Subtract 7 from each side

x+7-7 = -7 ±3i

x = -7 ±3i

6 0

3 years ago

Read 2 more answers

Please help .......You are guaranteed a minimum salary of $2000 per month PLUS 5.75% 5 points

RUDIKE [14]

Answer:

6600

Step-by-step explanation:

0.0575*80000=4600

4600+minimum salary which is 2000=6600

(can I get brainliest please)

5 0

2 years ago

How do you solve d+12=2 using mental math

n200080 [17]

By minusing 12 to both sides
d+12=2
-12=-12
d =-10

5 0

3 years ago

Our faucet is broken, and a plumber has been called. The arrival time of the plumber is uniformly distributed between 1pm and 7p

Ymorist [56]

Answer:

$E(A+B) = E(A)+E(B)=4+0.5 =4.5 hours$

$Var(A+B)= Var(A)+Var(B)=3+0.25 hours^2=3.25 hours^2$

Step-by-step explanation:

Let A the random variable that represent "The arrival time of the plumber ". And we know that the distribution of A is given by:

$A\sim Uniform(1 ,7)$

And let B the random variable that represent "The time required to fix the broken faucet". And we know the distribution of B, given by:

$B\sim Exp(\lambda=\frac{1}{30 min})$

Supposing that the two times are independent, find the expected value and the variance of the time at which the plumber completes the project.

So we are interested on the expected value of A+B, like this

$E(A +B)$

Since the two random variables are assumed independent, then we have this

$E(A+B) = E(A)+E(B)$

So we can find the individual expected values for each distribution and then we can add it.

For ths uniform distribution the expected value is given by $E(X) =\frac{a+b}{2}$ where X is the random variable, and a,b represent the limits for the distribution. If we apply this for our case we got:

$E(A)=\frac{1+7}{2}=4 hours$

The expected value for the exponential distirbution is given by :

$E(X)= \int_{0}^\infty x \lambda e^{-\lambda x} dx$

If we use the substitution $y=\lambda x$ we have this:

$E(X)=\frac{1}{\lambda} \int_{0}^\infty y e^{-\lambda y} dy =\frac{1}{\lambda}$

Where X represent the random variable and $\lambda$ the parameter. If we apply this formula to our case we got:

$E(B) =\frac{1}{\lambda}=\frac{1}{\frac{1}{30}}=30min$

We can convert this into hours and we got E(B) =0.5 hours, and then we can find:

$E(A+B) = E(A)+E(B)=4+0.5 =4.5 hours$

And in order to find the variance for the random variable A+B we can find the individual variances:

$Var(A)= \frac{(b-a)^2}{12}=\frac{(7-1)^2}{12}=3 hours^2$

$Var(B) =\frac{1}{\lambda^2}=\frac{1}{(\frac{1}{30})^2}=900 min^2 x\frac{1hr^2}{3600 min^2}=0.25 hours^2$

We have the following property:

$Var(X+Y)= Var(X)+Var(Y) +2 Cov(X,Y)$

Since we have independnet variable the Cov(A,B)=0, so then:

$Var(A+B)= Var(A)+Var(B)=3+0.25 hours^2=3.25 hours^2$

3 0

3 years ago

Find the surface area of the rectangular prism.

olganol [36]

Answer:

D. 270 cm2

Step-by-step explanation:

2*(15*5 + 15*3 + 5*3) = 270 cm2

8 0

3 years ago