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3 years ago

Please help me with this.

Mathematics

1 answer:

Nastasia [14]3 years ago

3 0

C,2 I agree with what the other comment said!!

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A. Student GPAs: Bob’s z-score z = + 1.71 μ = 2.98 σ = 0.36 b. Weekly work hours: Sarah’s z-score z = + 1.18 μ = 21.6 σ = 7.1 c.

hjlf

Answer:

a) $x = \mu +z*\sigma$

And replacing we got:

$x= 2.98 + 1.71*0.36 = 3.5956$

b) $x = \mu +z*\sigma$

And replacing we got:

$x= 21.6 + 1.18*7.1 = 29.978$

c) $x = \mu -z*\sigma$

And replacing we got:

$x= 150 - 1.35*40= 96$

Step-by-step explanation:

Previous concepts

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 Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Part a

Let X the random variable of interest for this case. We define the z score with the following formula:

$z=\frac{x-\mu}{\sigma}$

And for this case we know that $z = 1.71, \mu = 2.98,\sigma = 0.36$

If we solve for x from the z score formula we got:

$x = \mu +z*\sigma$

And replacing we got:

$x= 2.98 + 1.71*0.36 = 3.5956$

Part b

Let X the random variable of interest for this case. We define the z score with the following formula:

$z=\frac{x-\mu}{\sigma}$

And for this case we know that $z = 1.18, \mu = 21.6,\sigma = 7.1$

If we solve for x from the z score formula we got:

$x = \mu +z*\sigma$

And replacing we got:

$x= 21.6 + 1.18*7.1 = 29.978$

Part c

Let X the random variable of interest for this case. We define the z score with the following formula:

$z=\frac{x-\mu}{\sigma}$

And for this case we know that $z = -1.35, \mu = 150,\sigma = 40$

If we solve for x from the z score formula we got:

$x = \mu -z*\sigma$

And replacing we got:

$x= 150 - 1.35*40= 96$

5 0

3 years ago

One number is half another number. The sum of the two numbers is 57. Find the two numbers

nalin [4]

Let's call one number x and one number y.

x/2=y

x+y=57

We can set these equations equal to each other to solve for the numbers by subtracting x from both sides of the second equation. Now the equations are:

y=-x+57 and x/2=y

Since both equations equal y, they are also equal to each other:

-x+57=x/2

First, multiply both sides by 2:

-2x+114=x

Add 2x to both sides.

114=3x

Divide both sides by 3.

38=x

One of the numbers is 38. Now, we can plug 38 in for x in either of the equations to solve for y:

(38)+y=57

Subtract 38 from both sides:

y=19

The two numbers are 38 and 19.

I hope this helps :)

3 0

3 years ago

Fill in the table find the rule

lakkis [162]

Answer:

I'm sorry but where's the picture

8 0

2 years ago

4s*2+7s+2=0 Quadratic formula

natita [175]

Answer:

z=−215z=-215

Step-by-step explanation:

z=−215z=-215

6 0

3 years ago

Circumference of the circle

dimulka [17.4K]

Answer:

The formula of circumference in a circle is 3.14 times diameter.

Step-by-step explanation:

3.14×20=62.8

The circumference is 62.8

8 0

3 years ago