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FromTheMoon [43]

3 years ago

13

rachel enjoys exercising outdoors. today she walked 5 2/3 miles in 2 2/3 hours. what is rachel’s unit walking brats in miles per

hour and in hours per mile?

1 answer:

Ostrovityanka [42]3 years ago

5 0

I believe it is 8/17 miles per hour

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How do you do this???

Nesterboy [21]

You multiply what’s on top of that

7 0

3 years ago

Choose the correct simplification of the expression (2x7y)2(y5)3.

adoni [48]

Im taking this to mean (2 x^7 y)^2 (y^5)^3

= 4x^14 y^2 * y^15

= 4x^14 y^17 which is option 4

8 0

3 years ago

Read 2 more answers

A research group needs to determine a 90% confidence interval for the mean repair cost for all car insurance small claims. From

lutik1710 [3]

Answer:

a) $z = 1.645$

b) The should sample at least 293 small claims.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$ , which means that the answer of question a is z = 1.645.

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

(b) If the group wants their estimate to have a maximum error of $12, how many small claims should they sample?

They should sample at least n small claims, in which n is found when

$M = 12, \sigma = 124.88$ . So

$M = z*\frac{\sigma}{\sqrt{n}}$

$12 = 1.645*\frac{124.88}{\sqrt{n}}$

$12\sqrt{n} = 205.43$

$\sqrt{n} = \frac{205.43}{12}$

$\sqrt{n} = 17.12$

$\sqrt{n}^{2} = (17.12)^{2}$

$n = 293$

The should sample at least 293 small claims.

8 0

3 years ago

Given a table of values of a quadratic function, which of the following do you absolutely need in order to find its equation? *

nadya68 [22]

Answer:

The general form of a quadratic function is --> y = ax2 + bx + c

Since (0, -2) exists for the function, we can plug in those values:

-2 = a(0)2 + b(0) + c

-2 = 0 + 0 + c

-2 = c

So now our function so far is --> y = ax2 + bx - 2

We have two pairs of coordinates left: (-1, -8) and (3, -8).

First, plug in the first pair and simplify as much as you can:

-8 = a(-1)2 + b(-1) - 2

-8 = a - b - 2 ( add 2 to both sides )

-6 = a - b (stop here because we can't go further)

Second, plug in the second pair and simplify as much as you can:

-8 = a(3)2 + b(3) - 2

-8 = 9a + 3b - 2 ( add 2 to both sides )

-6 = 9a + 3b (stop here because we can't go further)

Now we have these two equations left:

a - b = -6

9a + 3b = -6

Now we solve for a and b using systems of equations, using one of three ways:

substitution

elimination

graphing (not my favorite, but it is doable)

Using substitution:

a - b = -6 can be rewritten as a = b - 6

plug into the second equation and solve for b

9(b - 6) + 3b = -6 (distribute the 9)

9b - 54 + 3b = -6 (combine all of the b's)

12b - 54 = -6 (add 54 to both sides)

12b = 48 (divide by 12 on both sides to isolate b)

b = 4

plug b into one of the original two equations

a - 4 = -6 (add 4 to both sides)

a = -2

The quadratic equation for this table is y = -2x2 + 4b - 2

6 0

2 years ago

Pleaeseee help on this probability question

crimeas [40]

there are 4 eggs total 3 plain and 1 gold

so you have a 1/4 probability of picking the gold egg

4 0

3 years ago