what is it step by step 7a - 4a when a = 8
Answer:
Step-by-step explanation:
7a - 4a
a = 8
so
7(8) - 4(8)
56 - 32 = 23
FINALLY! Someone asks for a step-by-step! TYSM!
Since a=8, we ae going to replace the a variables with 8.
7(8)-4(8)
7x8=56
4x8=32.
Now we subtract.
56-32=24.
---
hope it helps
The Washington, DC, region has one of the fastest-growing foreclosure rates in the nation, as 15,613 homes went into foreclosure during the one-year period ending in February 2008 (The Washington Post, June 19, 2008). Over the past year, the number of foreclosures per 10,000 homes is 131 for the Washington area, while it is 87 nationally. In other words, the foreclosure rate is 1.31% for the Washington, DC area and 0.87% for the nation. Assume that the foreclosure rates remain stable.
Required:
a. What is the probability that in a given year, fewer than 2 out of 100 houses in the Washington, DC area will go up for foreclosure?
b. What is the probability that in a given year, fewer than 2 out of 100 houses in the nation will go up for foreclosure?
c. Comment on the above findings.
Answer:
a) 0.6226 = 62.26% probability that in a given year, fewer than 2 out of 100 houses in the Washington, DC area will go up for foreclosure.
b) 0.7837 = 78.37% probability that in a given year, fewer than 2 out of 100 houses in the nation will go up for foreclosure.
c) The proportion of foreclosures in the Nation is lower than in Washington, which means that with a sample size of 100, it is likely to have a small number(fewer than 2) of foreclosures than Washington DC.
Step-by-step explanation:
For each home, there are only two possible outcomes. Either it goes into foreclosure, or it does not. The probability of a home going into foreclosure is independent of other homes. This means that we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
a. What is the probability that in a given year, fewer than 2 out of 100 houses in the Washington, DC area will go up for foreclosure?
The foreclosure rate is 1.31% for the Washington, DC area, which means that [tex]p = 0.0131[/tex]
We wanto to find, with [tex]n = 100[/tex]:
[tex]P(X < 2) = P(X = 0) + P(X = 1)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{100,0}.(0.0131)^{0}.(0.9869)^{100} = 0.2675[/tex]
[tex]P(X = 1) = C_{100,1}.(0.0131)^{1}.(0.9869)^{99} = 0.3551[/tex]
[tex]P(X < 2) = P(X = 0) + P(X = 1) = 0.2675 + 0.3551 = 0.6226[/tex]
0.6226 = 62.26% probability that in a given year, fewer than 2 out of 100 houses in the Washington, DC area will go up for foreclosure.
b. What is the probability that in a given year, fewer than 2 out of 100 houses in the nation will go up for foreclosure?
Foreclosure rate of 0.87% for the nation, which means that [tex]p = 0.0087[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{100,0}.(0.0087)^{0}.(0.9913)^{100} = 0.4174[/tex]
[tex]P(X = 1) = C_{100,1}.(0.0087)^{1}.(0.9913)^{99} = 0.3663[/tex]
[tex]P(X < 2) = P(X = 0) + P(X = 1) = 0.4174 + 0.3663 = 0.7837[/tex]
0.7837 = 78.37% probability that in a given year, fewer than 2 out of 100 houses in the nation will go up for foreclosure.
c. Comment on the above findings.
The proportion of foreclosures in the Nation is lower than in Washington, which means that with a sample size of 100, it is likely to have a small number(fewer than 2) of foreclosures than Washington DC.
The distance between City A and City B is 250 miles. A length of 1.4 feet represents this distance
on a certain wall map. City C and City D are 2.52 feet apart on this map. What is the actual
distance between City C and City D?
Answer:
2.66 miles hope it helps
WHO EVER ANSWERS FIRST WILL GET BRAINLY
3a = 42
Answer:
a=14
Step-by-step explanation:
Anyone know this please I really need help
Plz help it’s due tomorrow
Answer:
x=121 degrees
Step-by-step explanation:
Sorry if my work is a bit messy. If you need me to rewrite it i can
Anyone help?
.....hgzgxhlflhf
Answer:
it should be 152, can i please get brainliest
Step-by-step explanation:
Which fraction is shown by point D?
A. 1/3
B. 1/4
C. 3/3
D. 3/4
Answer:
C
Step-by-step explanation:
Hope dis helps
Determine if the sequence below is arithmetic or geometric and determine the common difference / ratio in simplest form. 2,5,8,... ?
Answer:
Arithmetic sequence with common difference of 3.
Step-by-step explanation:
Arithmetic sequence:
The difference between consecutive terms is always the same, and this difference is called common difference.
Geometric sequence:
The quotient between consecutive terms is always the same, and this quotient is called common ratio.
In this question:
5 - 2 = 8 - 5 = 3
5/2 = 2.5 different of 8/5 = 1.6
This means that it is an arithmetic sequence with common difference of 3.
A rocket fired upward from some initial distance above the ground. Its height (in feet) h, above the ground t seconds after it is fired is given by h(t)=-16t^2+160t+384
What is the rockets maximum height?
After it is fired, The rocket reaches the ground at t=____ seconds
Answer:
Part A)
784 feet in the air (after five seconds).
Part B)
After 12 seconds.
Step-by-step explanation:
The height h (in feet) of a rocket t seconds after being fired is modeled by the function:
[tex]h(t)=-16t^2+160t+384[/tex]
Part A)
We want to find the rocket's maximum height.
Since our function is a quadratic, the maximum height will occur at its vertex. The vertex of a quadratic is given by:
[tex]\displaystyle \Big(-\frac{b}{2a}\, f\Big(-\frac{b}{2a}\Big)\Big)[/tex]
In this case, a = -16, b = 160, and c = 384.
So, the vertex occurs at:
[tex]\displaystyle t=-\frac{160}{2(-16)}=\frac{160}{32}=5\text{ seconds}[/tex]
The maximum height is reached after five seconds.
Then the maximum height is:
[tex]h(t)_\text{max}=h(5)=-16(5)^2+160(5)+384=784\text{ feet}[/tex]
Part B)
When the rocket reaches the ground, its height h above the ground will be 0. Hence:
[tex]h(t)_\text{ground}=0=-16t^2+160t+384[/tex]
Solve for t. We can first divide both sides by -16:
[tex]t^2-10t-24=0[/tex]
Factor:
[tex](t-12)(t+2)=0[/tex]
Zero Product Property:
[tex]t-12=0\text{ or } t+2=0[/tex]
Solve for each case:
[tex]t=12\text{ or } t=-2[/tex]
Time cannot be negative. Hence, our only solution is:
[tex]t=12\text{ seconds}[/tex]
The rocket reaches the ground 12 seconds after it is fired.
I need help finding Angle P
Nora made 15 gallons of lemonade for a community picnic. She served 100 pints to the people. How many pints are leftover? Please help!
Answer:
There are 8 pints to a gallon so she makes 120 gallons, and since she served 100 pints then there are 20 pints left over.
Brainliest please?
Answer:43.1
Explanation
C = 2pi r
C = 2 x 3.14 x 6.87
C = 43.1 ft
This sounds like an answer....
can i get help pls??
Answer:
119 or 124
Step-by-step explanation:
Smith family had dinner at the restaurant. The cost of their meals was $45. They wanted to leave the waiter a 10% tip. They had a $50 bill.
How much change would they receive after paying for the food and leaving the tip?
Answer: 0.50
Step-by-step explanation: the tip was 4.50 (10% of 45) and so minus 50 and then minus 40 (50-45-4.50=0.50)
x<-20 pls answer. ........
Step-by-step explanation:
Do you need help graphing this or? Please specify!
11. John is building a wall. When he uses 750 bricks, the wall is 6 metres long and 1.25m high.
John wants the finished wall to be 10 metres long and 1.25 metres high.
How many more bricks does John need to finish the wall?
(Total 3 marks)
Answer:
750 blocks = 6m long
x blocks = 10m long
750×10 = 6x
7500 = 6x
divide both sides by 6
7500/6 = 6x/6
1250 = x
x = 1250
.
. . 1250 blocks are needed to finish the wall of 10m long
5. For the final touches, John wanted to paint the house using 3 colors. If he has 5
gallons of paint for each color, write an equation for the total number of gallons of
paint he has?
Answer:
3 x 5 = 15
Step-by-step explanation:
To explain this in short, John has 5 gallons of 3 colors, meaning that 3 x 5 = 15 would be the appropriate equation to finish this question. I hope this helps!
Please help! I will mark Best answer
Solve each equation.
1) 40+ 2r = 8(7r – 5)
A) 0
B) (14)
C) -14 D) 3
Answer:
A)
0
Step-by-step explanation:
It is zero.
0= 54r
Therefore r=0.
Answer:
x=0 so answer is A
Step-by-step explanation:
hope that helps
What is 5,729 + 2,729
Answer:
it equals 8458
Step-by-step explanation:
Caculator
what is the measure of angle 1?
a. 36
b. 86
c. 89
d. 94
Answer:
D, 94
Step-by-step explanation:
Angles of a triangle add up to 180 degrees. 180 - 29 - 65 = 86 Angles 1 and 2 add up to 180 degrees. 86 = 2 180 - 86 = 94 94 = 1
Hope this helps! If it did, please mark it as brainliest! It would help me out a lot! :D
Write an equivalent expression using the Distributive Property.35 + 21 = 7( + )
Answer:
$2200/month
$2200/month
Which situation explains when a system of equations has infinitely many solutions ?
Answer:
C. when they are the same line
The distance in feet karina swims in a race is represented by 6d-6, where d is the distance for each lap what is an expression equivalent to 6d-6
Answer:
its c
Step-by-step explanation:
I need help QUICK! with this difficult question
Answer:
Step-by-step explanation:
Write the equation of a line in slope-intercept form if m=2 and b=8.
Answer:
y=2x+8
Step-by-step explanation:
The slope intercept form is:
y=mx+b
with m and b already given, just plug in m and b and you will get your answer.
If US $1.00 is equivalent to EC $ 2.70, how much in US would one get from EC 297.00?
Which of the following is the solution to 2√30 + 3√10?
8√10
8√10
Cannot be simplified further
9√10
What is the slope and y-intercept of 3y = 3x -9?
Answer:
slope = 1
y-intercept = -3
Step-by-step explanation:
3y = 3x - 9
divide each side by 3
y = x - 3
slope = 1
y-intercept = -3
how could i find the value of this expression?
Answer:
you plug in the numbers
Step-by-step explanation:
Please mark brainliest!!
Answer:
√x⁴-y²
x²-y²
(x+y)(x-y)
when
x=3
y=-6
√x⁴-y²=(3-6)(3+6)=-3×9=-27 is your answer