The answer is 488.
22*17=374
12*19=228
228/2=114
374+114=488
Answer:
Step-by-step explanation:
The relation is not a function when x -value is same but y- values are different.
#1
#2
- k^2 - 5k = k + 7
- k^2 - 6k = 7
- k^2 - 6k + 9 = 16
- k - 3 = 4 ⇒ k = 7
- k - 3 = -4 ⇒ k = -1
#3
- k^3 - 5k^2 + 3k = -k
- k^3 - 5k^2 + 4k = 0
- k(k^2 - 5k + 4) = 0
- k = 0, k = 1, k = 4
#4
- |k + 1| + 2 = 8
- |k + 1| = 6
- k = 5, k = -7
Answer:
Step-by-step explanation:
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.
