Write 2 times 3 times n in a shorter way

At Hogwarts School of Witchcraft and Wizardry, Professor Snape was concerned about grade inflation, and suggested that the schoo

ExtremeBDS [4]

Answers:

The z scores are approximately:

Care of Magical Creatures: z = 0.333
Defense Against the Dark Arts: z = 0.583
Transfiguration: z = -0.263
Potions: z = -0.533

From those scores, we can say:

Best grade = Defense Against the Dark Arts
Worst grade = Potions

=====================================================

Further Explanation:

We'll need to convert each given score to a corresponding standardized z score.

The formula to use is

z = (x - mu)/sigma

where,

x = given grade for each class
mu = mean
sigma = standard deviation

Let's find the z score for the Care of Magical Creatures class

z = (x - mu)/sigma

z = (3.80 - 3.75)/(0.15)

z = 0.333 approximately

Repeat this process for the Defense Against the Dark Arts score.

z = (x - mu)/sigma

z = (3.60 - 3.25)/(0.60)

z = 0.583 approximately

And for the Transfiguration class as well

z = (x - mu)/sigma

z = (3.10 - 3.20)/(0.38)

z = -0.263 approximately

The negative z score means his grade below the average, whereas earlier the other scores were above the average since he got positive z scores.

Now do the final class (Potions) to get this z score

z = (x - mu)/sigma

z = (2.50 - 2.90)/(0.75)

z = -0.533 approximately

This grade is below average as well.

----------------------------

To summarize, we have these z scores

Care of Magical Creatures: z = 0.333
Defense Against the Dark Arts: z = 0.583
Transfiguration: z = -0.263
Potions: z = -0.533

Harry did his best in Defense Against the Dark Arts because the z score of 0.583 (approximate) is the largest of the four z scores. On the other hand, his worst grade is in Potions because -0.533 is the lowest z score.

3 0

2 years ago

What's the anwser to 5 6 7

ExtremeBDS [4]

5: n=135
6: n=3
7: n=214

3 0

3 years ago

Read 2 more answers

Use the value of the linear correlation coefficient r to find the percentage of the total variation that can be explained by the

Pie

Answer:

5.47% of the total variation between the two variables can be explained by the regression line.

Step-by-step explanation:

Given :

R value = 0.234

The R value is the correlation Coefficient ; which gives the type and level of correlation between two variables.

However, to Obtian the percentage variation which can be explained by by the regression line, we have to obtain the Coefficient of determination, R².

R² value is Obtained by taking the squared of the correlation Coefficient

Hence,

R² = 0.234² = 0.054756

R² = 0.05476 * 100% = 5.4756%

Hence, R² = 5.48%

This is interpreted as ; 5.47% of the total variation between the two variables can be explained by the regression line.

4 0

3 years ago

The standard deviation of a sample taken from population A is 17.6 for a sample of 25.

lawyer [7]

Answer:

The standard deviation of the sample mean differences is _5.23_

Step-by-step explanation:

We have a sample of a population A and a sample of a population B.

For the sample of population A, the standard deviation $\sigma_A$ is

$\sigma_A = 17.6$

The sample size $n_A$ is:

$n_A = 25$ .

For the sample of population B, the standard deviation $\sigma_B$ is

$\sigma_B = 21.2$

The sample size $n_B$ is:

$n_B = 30$ .

Then the standard deviation for the difference of means has the following form:

$\sigma=\sqrt{\frac{\sigma_A^2}{n_A}+\frac{\sigma_B^2}{n_B}}$

Finally

$\sigma=\sqrt{\frac{17.6^2}{25}+\frac{21.2^2}{30}}\\\\\sigma= 5.23$

7 0

4 years ago

Use the exponent properties to simplify the following <br> <img src="https://tex.z-dn.net/?f=%5Cfrac%7B%283x%5E2%29%5E3%7D%7B%28

IrinaK [193]

Answer:

$\dfrac{27}{16}x^2$

Step-by-step explanation:

The relevant properties are ...

(a^b)^c = a^(bc)

(a^b)/(a^c) = a^(b-c)

So, the expression simplifies to ...

$\dfrac{(3x^2)^3}{(2x)^4}=\dfrac{3^3x^{2\cdot 3}}{2^4x^4}=\dfrac{27}{16}x^{6-4}=\dfrac{27}{16}x^{2}$

6 0

4 years ago