$s(t)= \int\limits^{35}_0 {v(t)} \, dt \\ =\int\limits^{35}_0 {(20+5cos(t))} \, dt \\ =[20t+5sin(t)]^{35}_0 \\ =(20(35)+5sin(35))-(20(0)+5sin(0)) \\ =700+2.868=702.868 \, feet$

8 0

2 years ago

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

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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.

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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

1 year ago