X time 0.8 (or 80 percent)= 15
so 15/0.8=X
18.75
Okay first you need to convert 0.2 to a percentage which would be 20% then 20% + 20% = 40% then it says he read 50%, 50% of 36 means that you have to multiply 36 two times to get, 72 then you do 72 * 40% = 28.8 = 29 + 72 = 101 pages in all then 101- 40%= 60.6 is how many pages were read on Monday and Tuesday.
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.
Answer:
1. A number decreased by seven.
2. A number increased by nine.
3. The product of six and a number, divided by eight.
4. The product of three and a number increased by five is equal to twenty.
5. The product of two and a number increased by eight is equal to twenty-three.
Step-by-step explanation:
1. x-7
A number decreased by seven.
2. y+9
A number increased by nine.
3. 6m/8
The product of six and a number, divided by eight.
4. 3y+5 =20
The product of three and a number increased by five is equal to twenty.
5. 2(x+8)= 23
The product of two and a number increased by eight is equal to twenty-three.
