A line contains the point (3, 5). If the line has a negative slope, which of these points could also be on the line?

Suppose a population has a mean of 400 and a standard deviation of 24. if a random sample of size 144 is drawn from the populati

Drupady [299]

Find the critical value or test statistic.
$z = \frac{m - \mu}{\sigma/\sqrt{n}} = \frac{404.5 - 400}{24/\sqrt{144}} = \frac{4.5}{2} = 2.25$

Find P(z > 2.25) using a normal distribution table

P(z > 2.25) = 0.0122

6 0

2 years ago

Researchers at a pharmaceutical company have found that the effective time duration of a safe dosage of pain relief drug is norm

FrozenT [24]

Answer:

a) $P(1$

b) $P(X$

Step-by-step explanation:

1) 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".

2) Part a

Let X the random variable that represent the duration of a safe dosage of pain relief drug, and for this case we know the distribution for X is given by:

$X \sim N(1.5,0.8)$

Where $\mu=1.5$ and $\sigma=0.8$

We are interested on this probability

$P(1$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

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

If we apply this formula to our probability we got this:

$P(1$

And we can find this probability on this way:

$P(-0.625$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(-0.625$

3) Part b

We are interested on this probability

$P(X$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

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

If we apply this formula to our probability we got this:

$P(X$

And we can find this probability on this way:

$P(z$

6 0

3 years ago

Algebra 2 Standard Deviation

Illusion [34]

Answer:

don't have answer but have how to do them

Step-by-step explanation:

What are z-scores?

A z-score measures exactly how many standard deviations above or below the mean a data point is.

Here's the formula for calculating a z-score:

z=\dfrac{\text{data point}-\text{mean}}{\text{standard deviation}}z=

standard deviation

data point−mean

z, equals, start fraction, start text, d, a, t, a, space, p, o, i, n, t, end text, minus, start text, m, e, a, n, end text, divided by, start text, s, t, a, n, d, a, r, d, space, d, e, v, i, a, t, i, o, n, end text, end fraction

Here's the same formula written with symbols:

z=\dfrac{x-\mu}{\sigma}z=

σ

x−μ

z, equals, start fraction, x, minus, mu, divided by, sigma, end fraction

Here are some important facts about z-scores:

A positive z-score says the data point is above average.

A negative z-score says the data point is below average.

A z-score close to 000 says the data point is close to average.

A data point can be considered unusual if its z-score is above 333 or below -3−3minus, 3. [Really?]

Want to learn more about z-scores? Check out this video.

Example 1

The grades on a history midterm at Almond have a mean of \mu = 85μ=85mu, equals, 85 and a standard deviation of \sigma = 2σ=2sigma, equals, 2.

Michael scored 868686 on the exam.

Find the z-score for Michael's exam grade.

\begin{aligned}z&=\dfrac{\text{his grade}-\text{mean grade}}{\text{standard deviation}}\\ \\ z&=\dfrac{86-85}{2}\\ \\ z&=\dfrac{1}{2}=0.5\end{aligned}

z

=

standard deviation

his grade−mean grade

=

2

86−85

=

2

1

=0.5

Michael's z-score is 0.50.50, point, 5. His grade was half of a standard deviation above the mean.

Example 2

The grades on a geometry midterm at Almond have a mean of \mu = 82μ=82mu, equals, 82 and a standard deviation of \sigma = 4σ=4sigma, equals, 4.

Michael scored 747474 on the exam.

Find the z-score for Michael's exam grade.

\begin{aligned}z&=\dfrac{\text{his grade}-\text{mean grade}}{\text{standard deviation}}\\ \\ z&=\dfrac{74-82}{4}\\ \\ z&=\dfrac{-8}{4}=-2\end{aligned}

z

=

standard deviation

his grade−mean grade

=

4

74−82

=

4

−8

=−2

Michael's z-score is -2−2minus, 2. His grade was two standard deviations below the mean.

https://www.khanacademy.org/math/statistics-probability/modeling-distributions-of-data/z-scores/a/z-scores-review

this should help

6 0

3 years ago

Jadon has 4 feet of ribbon to decorate pockets. He needs 1/3 foot of ribbon to decorate each pocket. How many pockets will jadon

jolli1 [7]

Answer:

4 feet of ribbon ÷ 1/3 foot riboon = 12 pockets

5 0

2 years ago

Solve 2x2 8x - 12 = 0 by completing the square. show step-by-step solution

malfutka [58]

Group x terms
(2x^2+8x)-12=0
undistribute 2
2(x^2+4x)-12=0
take 1/2 of 4 and square it, add negative and positive of it insde (2^2=4)
2(x^2+4x+4-4)-12=0
factor perfect square
2((x+2)^2-4)-12=0
distribute
2(x+2)^2-8-12=0
2(x+2)^2-20=0
add 20 to both sides
2(x+2)^2=20
divide both sides by 2
(x+2)^2=10
sqrt both sides, remember to take positive and negative root
x+2=+/-√10
minus 2 both sides

x=-2+√10 and -2-√10

8 0

3 years ago