Please Help!!!! I will give brainliest!!!

Gary bought an MP3 player at a 20% discount sale for $40. What was the original price of the MP3 player?

marta [7]

40*.20=8.00
40 - 8=32
answer32
hope you understand.
explain:]
40*.20=8
and second time i do ( - ) becouse they said 20% discount discount main is ( - )
so i do ( - ) i think now you understand.

5 0

3 years ago

Let X and Y be joint continuous random variables with joint density function fpx, yq " # e ´y y 0 ă x ă y, 0 ă y ă 8 0 otherwise

Assoli18 [71]

Answer:

For X, the parameter

is λX = 1/2 and for Y it is λY = 1. Using the formula sheet, Mean is

E[Z] = E[X] + 2E[Y ] = 4. Variance is V ar(Z) = V ar(X) + 4V ar(Y ) = 8.

6 0

3 years ago

Is the ans i got correct?<br>the total surface area is 33.8cm² <br>

ElenaW [278]

Given:

A prism with height 5 cm and equilateral triangular base with side 2 cm.

To find:

The total surface area of the prism.

Solution:

Area of an equilateral triangle is:

$A_1=\dfrac{\sqrt{3}}{4}a^2$

Where, a is the side length.

Putting $a=2$ , we get

$A_1=\dfrac{\sqrt{3}}{4}(2)^2$

$A_1=\dfrac{\sqrt{3}}{4}(4)$

$A_1=\sqrt{3}$

$A_1\approx \sqrt{3}$

The base and top of the prism are congruent so their area must be equal.

The lateral surface area of the prism is:

$LA=Ph$

Where, P is the perimeter of the base and h is the height of the prism.

The lateral surface area of the prism is:

$A_2=(2+2+2)5$

$A_2=(6)5$

$A_2=30$

Now, the total surface area is the sum of areas of bases and lateral surface area.

$A=2A_1+A_2$

$A=2(1.73)+30$

$A=3.46+30$

$A=33.46$

Therefore, the total surface area is 33.46 cm².

8 0

2 years ago

Evaluate the function for x = 2 and x = 6.<br> f(x) = -(x - 2)<br> need help like asap

Kay [80]

Answer:

zero and negative four

I hope that's what you meant I don't know

Step-by-step explanation:

f(x) = -(x - 2)

=-(2-2)

=0

f(x) = -(x - 2)

=-(6-2)

=-4

5 0

3 years ago

Considering the number of questions incorrect from classmates on a quiz {10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19,

IrinaK [193]

Answer:

According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02

Step-by-step explanation:

We are given the following data in the question:

10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19, 20

Formula:

$\text{Standard Deviation} = \sqrt{\displaystyle\frac{\sum (x_i -\bar{x})^2}{n-1}}$

where $x_i$ are data points, $\bar{x}$ is the mean and n is the number of observations.

$Mean = \displaystyle\frac{\text{Sum of all observations}}{\text{Total number of observation}}$

$Mean =\displaystyle\frac{225}{15} = 15$

Sum of squares of differences = 25 + 16 + 9 + 4 + 4+ 4 + 1 + 0+ 1+ 1 + 4 + 9 + 9+ 16 + 25 = 128

$S.D = \sqrt{\dfrac{128}{14}} = 3.02$

Empirical rule:

According to this rule almost all the data lies within three standard deviation of the mean for a normal distribution.
About 68% of data lies within one standard deviation of the mean.
About 95% of data lies within two standard deviations of mean.
Arround 99.7% of data lies within three standard deviation of mean.

Thus, by empirical rule,

$\mu \pm 1\sigma = 15\pm (3.02) = (11.98,18.02)$

According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02

5 0

3 years ago