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3 years ago

I'm stuck on b.please help me!!!!

Mathematics

1 answer:

Sloan [31]3 years ago

5 0

The area under the speed curve tells you how much distance the vehicle covers.

The distance for first 30 s corresponds to the area of a rectangle with height k m/s and length 30 s, or

(k m/s) (30 s) = 30k m

The distance for the last 20 s corresponds to the area of triangle with height k m/s and length 20 s, or

1/2 (k m/s) (20 s) = 10k m

If the total distance traveled was 1.7 km = 1700 m, then

30k + 10k = 1700

40k = 1700

k = 42.5

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What is the volume hight-3 and wingth-10

inn [45]

Answer:

30 SQUARE units

Step-by-step explanation:

Since the problem only includes two dimensions, we solve for area, not volume. Area=width*height, or 3*10=30. Because we're solving for area the answer is 30 square units.

5 0

3 years ago

A student wanted to construct a 95% confidence interval for the mean age of students in her statistics class. She randomly selec

VMariaS [17]

Answer:

$19.1-3.355\frac{1.5}{\sqrt{9}}=17.42$

$19.1+3.355\frac{1.5}{\sqrt{9}}=20.78$

And the best option would be:

C. [17.42,20.78]

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

$\bar X=19.1$ represent the sample mean

$\mu$ population mean (variable of interest)

s=1.5 represent the sample standard deviation

n=9 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=9-1=8$

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,8)".And we see that $t_{\alpha/2}=$

Now we have everything in order to replace into formula (1):

$19.1-3.355\frac{1.5}{\sqrt{9}}=17.42$

$19.1+3.355\frac{1.5}{\sqrt{9}}=20.78$

And the best option would be:

C. [17.42,20.78]

5 0

3 years ago

Which graph represents a linear function? (4 points)

leonid [27]

Answer:

On the surface, it seems easy. Can you think of the integers for x, y, and z so that x³+y³+z³=8? Sure. One answer is x = 1, y = -1, and z = 2. But what about the integers for x, y, and z so that x³+y³+z³=42?

That turned out to be much harder—as in, no one was able to solve for those integers for 65 years until a supercomputer finally came up with the solution to 42. (For the record: x = -80538738812075974, y = 80435758145817515, and z = 12602123297335631. Obviously.)

Step-by-step explanation:

4 0

2 years ago

Can someone help me please

Yakvenalex [24]

Answer:

the third one ( -7+u+8t)

Step-by-step explanation:

first you add the ts together and you get 8. Then u keep the U and cancel out the +2 nad the -2. Then you are left with your answer. have a nice day

7 0

3 years ago

Solve for x: 5x\10=2 is it (a) 1 (b) 4 (c) 5 (d) 20

OleMash [197]

(b) 4

5(4)/10=20/10=2

6 0

3 years ago

I'm stuck on b.please help me!!!!​

I'm stuck on b.please help me!!!!