During a test period, an experimental group of 10 vehicles using an 85 percent ethanol-gasoline mixture showed mean CO2 emissions of 667 pounds per 1000 miles, with a standard deviation of 20 pounds. A control group of 14 vehicles using regular gasoline showed mean CO2 emissions of 679 pounds per 1000 miles with a standard deviation of 15 pounds. At α = 0.05, in a left-tailed test (assuming equal variances) the test statistic is:______.
A. 1.321.
B. -2.508.
C. -2.074.
D. -1.717.

Answers

Answer 1

Answer:

-1.683

Step-by-step explanation:

Given :

Group 1 :

x1 = 667 ; n1 = 10 ; s1 = 20

Group 2 :

x2 = 679 ; n2 = 14 ; s2 = 15

The test statistic assuming equal variance :

x1 - x2 / √[Sp² * (1/n1 + 1/n2)]

sp² = [(n1 - 1)*s1² + (n2 - 1)*s2²] ÷ (n1 + n2 - 2)

Sp² = [(10 - 1)*20² + (14 - 1)*15²] = 296.59

Test statistic =

(667 - 679)/ √[296.59 * (1/10 + 1/14)]

-12 / 7.1304978

Test statistic = - 1.682


Related Questions

Please help! What is the value of x?

Answers

Answer:

I think the bigger triangle is x2 of the smaller triangle so if the base is 20ft then the hight is 12

Which of the following points lies on the line 2x+3y=5?
A. (2,3)
B. (2,1)
C. (-2,3)
D. (-2,0)

Answers

Answer:

B(2,1). And C(-2,3)

Step-by-step explanation:

Tbh, you can just plug the numbers into the original equation :2x+3y=5

A.2x2+3x3=13 ≠5

B.2x2+3x1=5=5

C.-2x2+3x3=5=5

D.-2x2+3x0=-4≠5

So the answer is B and C lies on the line

State if the two triangles are congruent. If they are state how you know.
Help me

Answers

Answer:

not congruent

Step-by-step explanation:

The two triangles have a common side. That makes 1 pair of congruent sides.

The triangles have another pair of congruent sides that is shown.

There is also 1 pair of congruent angles.

Since there is no SSA method of proving triangles congruent, the answer is the first choice:

not congruent

113-5.[ 2 3-( 2 3+(6))]

Answers

Answer:

143 should be correct

Step-by-step explanation:

hope this helps

There are 14 European cities that Sam would eventually like to visit. On his next vacation, though, he only has time to visit 3 of the cities: one on Monday, one on Tuesday, and one on Wednesday. He is now trying to make a schedule of which city he'll visit on which day. How many different schedules are possible? (Assume that he will not visit a city more than once.)

Answers

Answer:

2184 different schedules

Step-by-step explanation:

Sam can make different schedules of the same three cities, so order of cities does matter, but no repetition is allowed. This makes this a permutation without repetition.

When we choose from n items, and we choose r of them, our formula is

n! / (n-r)!. We have 14 things to choose from, and 3 to choose, so our formula becomes

14! / (14-3)! = 14!/11! = 14*13*12 = 2184 different schedules

look at picture for problem​

Answers

add 2 3/4 and 2 1/2 and you’ll get ur answer. area means total and when u see area, it means add

Find the slope of the line passing through the points (3,-1) and (3, -6).

Answers

Answer:

Undefined

Step-by-step explanation:

Slope formula:

y2-y1/x2=x1

In (3,-1), 3 is x1 and -1 is y1

In (3, -6), 3 is x2 and -6 is y2

-6-(-1)/3-3

Which is -5/0

And that couldn't happen in a slope

So the answer is undefined

Hope this helps!

Which equation shows the inverse property of multiplication?
4 + (-4) = 0
-8 + (-3) = -3 + (-8)
2 times one-half = 1

Answers

Answer 3 it’s answering itself as it is the only multiplication problem

Jose is trying to pick out an outfit for the first day of school. He can choose from 2 pairs of pants, 6 t-shirts, and 3 pairs of shoes. How many different outfits does Jose have to choose from?

Answers

Answer:

Jose has 36 outfits in total, just multiply all the numbers together

Step-by-step explanation:

a
Joshua is flying a kite, holding his hands a distance of 3.75 feet above the
ground and letting all the kite's string play out. He measures the angle of
elevation from his hand to the kite to be 28°. If the string from the kite to his
hand is 140 feet long, how many feet is the kite above the ground? Round
your answer to the nearest hundredth of a foot if necessary.

Answers

Answer:

Step-by-step explanation:

Assuming the ground is level

h = 3.75 + 140sin28

h = 69.47601...

h = 69.48 ft.

The height of the kite above the ground is 69.48 ft

Right angle triangle:A right angle triangle is a triangle that has one of its angle as 90 degrees. Therefore,

Using trigonometric ratio, the opposite side of the triangle formed can be calculated as follows:

sin 28° = opposite / hypotenuse

sin 28° = x / 140

x = 140 sin 28

x = 140 × 0.46947156278

x = 65.72601879

x = 65.73

The height of the kite from the ground = 65.73 + 3.75 = 69.48 feet

learn more on right triangle here: https://brainly.com/question/25892318

Use square roots to solve the equation x ^ 2 = - 25 over the complex numbers. Select any solutions that apply A.-5 B. -5i C. -5i^2 D.5i

Answers

Answer:

B. [tex]-5i[/tex]

D. [tex]5i[/tex]

Step-by-step explanation:

Remember that the imaginary unit is equal to:

[tex]i^2 = -1[/tex]

And getting the square root in both sides of the equation we get:

[tex]i = \sqrt{-1} \quad \land \quad -i = \sqrt{-1}[/tex]

The with our expression we develop of the next way:

[tex]x^2 = -25\\x = \sqrt{-25}[/tex]

However in the real numbers doesn't exist solution for such operation then you use the complex numbers for represent the operation.

[tex]x = 5i \quad \land \quad x = -5i[/tex]

In this occasion we use [tex]i[/tex] and [tex]-i[/tex] because both represent a negative square root, so our final answer is:

B and D

7(2e-1)-3=6+6e pls help and do step by step

Answers

Answer:

e = 2

Step-by-step explanation:

7(2e - 1) - 3 = 6 + 6e

14e - 7 - 3 = 6 + 6e

14e - 10 = 6 + 6e

14e - 6e - 10 = 6

8e - 10 = 6

8e = 6 + 10

8e = 16

8e/8 = 16/8

e = 2

Recheck:

7(2e - 1) - 3 = 6 + 6e

7(2(2) - 1) - 3 = 6 + 6(2)

7(4 - 1) - 3 = 6 + 12

7(3) - 3 = 18

21 - 3 = 18

18 = 18 ✅

-3x-8? I would like to know the steps also

Answers

Answer:

24

Step-by-step explanation:

a - and a - make a +

so -3 x -8 becomes positive

so 3 x 8 = 24

Plzzzz help I REALLY NEED HELP

Write a division problem with 1/3 as the dividend 3 as divisor. The find the quotient.

Answers

Answer:

1/9

Step-by-step explanation:

answer would be 0.333

Find the area of the triangle

Answers

Answer:

5/2 units²

Step-by-step explanation:

Area of triangle = 1/2 x base x altitude => 1/2 x 5 x 1=> 5/2

Conclusion:

Therefore, the area of the triangle is 5/2 units².

Hoped this helped.

[tex]GeniusUser[/tex]

There were 120 tickets sold for a band concert and 3/4 of those were student tickets how many adult tickets for the concert were sold

Answers

Answer:

30 because if u divided 120 by 4 its 30 and the parents get 1/4 so its 3....... 30/120

Help help help help help help pelsss

Answers

Answer:

angle 4 is also 75 degrees

Step-by-step explanation:

How do you know where to place a decimal in a quotient?

Answers

Divide. Place decimal point in the quotient. It should be placed directly above the decimal point in the dividend.

solve the graph fjsdjshfdkjfd

Answers

Answer:

y=-2x+3

Step-by-step explanation:

Comment if you need steps.



Rachel has $10.00. She wants to buy a book that costs $6.79. Will she have enough
money left over to buy a pen for $3.50? Explain.

Answers

Answer:

No

Step-by-step explanation:

Because 10 - 6.79 = 3.21

Rachel will not have enough money left over to buy a pen for cost $3.50.

What is Subtraction?

Subtraction can be done for any numbers or algebraic expressions. It is the process of taking out certain value from a given amount of number.

The process of subtraction can also be termed as finding difference. It is one of the basic operation in mathematics.

A number 'b' subtracted from 'a' is denoted as a - b, read as a minus b.

Total money Rachel has = $10.00

Cost of book = $6.79

If she buy the book,

Remaining money = $10.00 - $6.79

                              = $3.21

Cost of pen = $3.50, which is greater than the remaining money. So Rachel can't buy the pen.

Hence Rachel will not have enough money to buy a pen for $3.50 because she only has a balance of $3.21.

To learn more about Subtraction, click on the link given below :

https://brainly.com/question/2346316

#SPJ2

Select the range of the following relation { (20, 2), (30, 4), (40, 1), (50, 2)} A {1, 2, 3) B {1,2,4} C {1, 2, 3, 4) D {2, 3, 4)​

Answers

Answer:

B  {1,2,4}

Step-by-step explanation:

I took the test

10. A wildfire in Montana destroyed 240,000 acres in 3 days. At this rate, how many
acres were destroyed per hour?

Answers

Answer:

Approximately 3,333 acres per hour.

Step-by-step explanation:

Let's first find out how many hours are in 3 days.

There are 24 hours in one day.

24 times 3 = 72.

There are 72 hours in 3 days.

So the wildfire is destroying 240,000 acres every 72 hours.

240,000 divided by 72 = 3,333.3333, which is about

3,333 acres per hour.

The number of acres of land that were destroyed per hour is 3,333.33 acres.

Given the following data:

Land destroyed = 240,000 acres.Time = 3 days.

To calculate the number of acres of land that were destroyed per hour:

How to solve a word problem.

In this exercise, you're required to determine how many acres of land in Montana were destroyed by the wildfire per hour. Thus, we would first of all convert the value of time in days to hours and then divide the acres of land by it.

Conversion:

1 day = 24 hours.

2 days = 48 hours.

3 days = 72 hours.

For the acres destroyed per hour, we have:

[tex]Land=\frac{240000}{72}[/tex]

Land = 3,333.33 acres.

Read more on word problems here: https://brainly.com/question/13170908

PLEASE HELP! Look at the image and please help me

Answers

Answer:

Step-by-step explanation:

its b

ya this person is a bot be careful


charissa2

Answers

Be your self and always be kinda

Yi = 4.0 + 1.5Xi
a. Interpret the Y intercept, b0.

Answers

Answer:

Divide each term in  Y i  =  4  +  1.5 X i  by  i  and simplify.

Y  =  −  4 i  +  1.5 X

Step-by-step explanation:

can anyone please help? I'm stuck on this problem​

Answers

Answer:

I think 38.7 if you do<j it would be 38.7

Help!!!! Need this asap!!!

Answers

Answer:

the graph is in link

Step-by-step explanation:

y ..... means full  line and shading above the line

Y< ......means  doted  line and shading below the line

A) solution is overlapping shaded part

B) (10,5)

plug in point in inequalities and check if it's true; if it's true you showed that solution is correct

1. 5-1/2*10 + 2 1/2

 5 -5 + 2 1/2

 5 -2 1/2 TRUE

2. 51/5*10 + 6

  5< 2 + 6

5< 8  TRUE

F(t) = 200(0.95)^t
What is the rate of change?

Answers

Answer:

f(t)=-5%

Step-by-step explanation:

Answer:

the rate of change is 5%

Step-by-step explanation:

Given : Function

To find: What is the rate of change?

Solution :

The given function is an exponential function as it is in form

in which b is the factor of rate,

If b=1+r then r is the growth rate

If b=1-r then r is the decay rate.

We have given b=0.95

So, 0.95=1-r

r=1-0.95

r=0.05

i.e, It is a decay rate with 5%.

Therefore, The rate of change is 5%.

The difference of p and 4

Answers

Difference Means subtraction

p-4

Or

4-p

There is a unlike term [p] and 4.So we can't subtract.We can only subtract when there is p and 4p(4p-p).Answer would be 3 p.

9. YOU BE THE TEACHER Your friend
says 9 divided by 2.5 is about 3. Is your friend's
estimate reasonable? Explain.

Answers

Answer:

Step-by-step explanation:

Yes, it's reasonable.

What you are doing is solving the question by rounding. You come up with an answer. Suppose you loose the decimal somewhere and you get 0.36? Is that reasonable? Do you just write the answer in the provided blank and move on. What now?

You get it wrong?!!

But your estimate should be about 9/3 = 3. Now you look at your calculator with great misgivings, because it made a mistake. Did it or did you? Well ultimately you did, but you have to blame something. So the calculator takes the heat.

Who  knows? Maybe the decimal doesn't work. It's stuck or something. In any event you should be aware that there's no way the answer could be 0.36 when you estimate it to be 3.

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