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3 years ago

9

scores on a test have a mean of 67 and a standard devation of 10. michelle has a score of 87. convert michelle score to a z-scor

e?

1 answer:

klasskru [66]3 years ago

6 0

Answer:

z-score = 2.

Step-by-step explanation:

The z-score = (x - m) / d where x =the person's score, m = the mean and d = the standard deviation.

So we have (87-67)/10

= 2.

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At a local dealership 30% of cars are SUVs, 50% of the cars are painted white, and 15% are white and an SUV. If we randomly sele

alex41 [277]

Answer:

1/8, 0.0625 , or 6.25%

Step-by-step explanation:

50% of the cars are painted white.

1/2 * 1/2 = 1/4 * 1/4 = 1/8

Probability of A occuring 4 time(s) = 0.54 = 0.0625

Probability of A NOT occuring = (1 - 0.5)4 = 0.0625

Probability of A occuring = 1 - (1 - 0.5)4 = 0.9375

6 0

3 years ago

Marie, Shelia, and Martha bought snacks for a girl's sleepover. They each bought the items shown in the following table at the l

creativ13 [48]

Using a system of equations, it is found that the unit prices are:

$2.25 for a bag of chips.

$1.50 for a liter of pop.

$1.75 for a chocolate bar.

For the system:

x is the unit price of a bag of chips.

y is the unit price of liter of pop.

z is the unit price for a chocolate bar.

From the table, the equations are:

$2x + 2y + z = 9.25$

$3x + 4y + z = 14.50$

$x + 3y + 3z = 12$

Replacing the <u>first equation on the second and the third:</u>

$z = 9.25 - 2x - 2y$

$3x + 4y + z = 14.50$

$3x + 4y + 9.25 - 2x - 2y = 14.50$

$x + 2y = 5.25$

$x = 5.25 - 2y$

$x + 3y + 3z = 12$

$x + 3y + 3(9.25 - 2x - 2y) = 12$

$-5x - 3y = -15.75$

$5x + 3y = 15.75$

Since $x = 5.25 - 2y$ :

$5(5.25 - 2y) + 3y = 15.75$

$-7y = -10.5$

$y = \frac{10.5}{7}$

$y = 1.5$

Then:

$x = 5.25 - 2y = 5.25 - 2(1.5) = 2.25$

$z = 9.25 - 2x - 2y = 9.25 - 2(2.25) - 2(1.5) = 1.75$

The unit prices are:

$2.25 for a bag of chips.

$1.50 for a liter of pop.

$1.75 for a chocolate bar.

A similar problem, also solved using a system of equations, is given at brainly.com/question/14183076

4 0

2 years ago

The length of a rectangle is increasing at a rate of 6 cm/s and its width is increasing at a rate of 5 cm/s. When

atroni [7]

Answer:

The area of the rectangle is increasing at a rate of 84 square centimeters per second.

Step-by-step explanation:

The area for a rectangle is given by the formula:

$A=w\ell$

Where <em>w</em> is the width and <em>l</em> is the length.

We are given that the length of the rectangle is increasing at a rate of 6 cm/s and that the width is increasing at a rate of 5 cm/s. In other words, dl/dt = 6 and dw/dt = 5.

First, differentiate the equation with respect to <em>t</em>, where <em>w</em> and <em>l</em> are both functions of <em>t: </em>

$\displaystyle \frac{dA}{dt}=\frac{d}{dt}\left[w\ell]$

By the Product Rule:

$\displaystyle \frac{dA}{dt}=\frac{dw}{dt}\ell +\frac{d\ell}{dt}w$

Since we know that dl/dt = 6 and that dw/dt = 5:

$\displaystyle \frac{dA}{dt}=5\ell + 6w$

We want to find the rate at which the area is increasing when the length is 12 cm and the width is 4 cm. Substitute:

$\displaystyle \frac{dA}{dt}=5(12)+6(4)=84\text{ cm}^2\text{/s}$

The area of the rectangle is increasing at a rate of 84 square centimeters per second.

8 0

3 years ago

F (x + 5) - 2(4x - 1) = 0, what is the value of x?

schepotkina [342]

It is a.1

(1+5) - 2(4(1)-1) = 0

(6) - 2(3) = 0

6 - 6 = 0

0=0

4 0

3 years ago

Please help me with this

Ronch [10]

Think of it as two rectangular prisms next to each other, and find the volume of each one separately.

The big one on the left has a volume of 4 * 12 * 6, or 288.

The smaller one on the right has a volume of 2 * 6 * 6, or 72.

288 + 72 = 360. 360 cubic feet of water are needed.

8 0

3 years ago