The price of a skateboard is reduced by 25% . The original price was $ 120. Find the new price .

raketka [301]

I think I is the Answer

5 0

3 years ago

a polynomial function p(x) with rational coefficients has the given roots (10-square root of 6 and 4i). Find two additional root

Aleonysh [2.5K]

Answer:

6px

Step-by-step explanation:

hope this help

8 0

2 years ago

1. Emily filled an empty horse trough with water. The water level, in centimeters, is proportional to time elapsed, in minut

castortr0y [4]

(a) The rate that the point 8,28 represents is 3.5 cm/s since 28/8 = 3.5
(b) The unit rate is 3.5 cm/s since the rate is constant.
(c) The two points lie on the same line and that both points results to a rate of 3.5 cm/s.<span />

6 0

3 years ago

Brass is made from a mixture of copper and other elements. a mixture that is 80% copper is combined with a mixture that is 60% c

algol [13]

The equation that can be used to find x, the amount of the 60% mixture used to create the 65% mixture is:

0.60*x + 0.80*(100 - x) = 0.65*(100).

<h3>Which equation we should use?</h3>

First, let's define two variables:

x = pounds of the 60% copper brass.
y = pounds of the 80% copper brass.

We know that we want to make 100 lb of 65% copper brass, then we must have that:

x + y = 100

And the percentage of copper before and after mixing must be the same, so we can write:

0.60*x + 0.80*y = 0.65*(x + y).

(where the percentages are written in decimal form).

Then we have a system of equations:

x + y = 100

0.60*x + 0.80*y = 0.65*(x + y).

To get a single equation, we can isolate the variable "y" on the first equation:

y = 100 - x

Now we replace that in the other equation:

0.60*x + 0.80*(100 - x) = 0.65*(100).

This is what we wanted to get, an equation that can be used to find x, the amount of the 60% mixture used to create the 65% mixture.

If you want to learn more about systems of equations:

brainly.com/question/13729904

#SPJ1

4 0

2 years ago

Suppose that a fast food restaurant decides to survey its customers to gauge interest in a breakfast menu. After surveying multi

Harlamova29_29 [7]

Answer:

$ME= \frac{Width}{2}=\frac{0.078}{2}=0.039$

$\hat p =0.688+0.039=0.727$

$\hat p =0.766-0.039=0.727$

Step-by-step explanation:

Assuming that the confidence interval is (0.688; 0.766)

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".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

Use the confidence interval to find the point estimate and margin of error for the proportion

The margin of error is given by :

$Me=z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

And for our case we can find the width of the confidence interval like this:

Width =0.766-0.688=0.078

And the estimation for the margin of error would be given by:

$ME= \frac{Width}{2}=\frac{0.078}{2}=0.039$

Now we can find th point of estimate adding the margin of error to the lower limit of the interval or subtracting the margin of error to the upper limit, like this:

$\hat p =0.688+0.039=0.727$

$\hat p =0.766-0.039=0.727$

4 0

3 years ago