Answer:
The number of students who scored more than 90 points is 750.
Step-by-step explanation:
Quartiles are statistical measures that the divide the data into four groups.
The first quartile (Q₁) indicates that 25% of the observation are less than or equal to Q₁.
The second quartile (Q₂) indicates that 50% of the observation are less than or equal to Q₂.
The third quartile (Q₃) indicates that 75% of the observation are less than or equal to Q₃.
It is provided that the first quartile is at 90 points.
That is, P (X ≤ 90) = 0.25.
The probability that a student scores more than 90 points is:
P (X > 90) = 1 - P (X ≤ 90)
= 1 - 0.25
= 0.75
The number of students who scored more than 90 points is: 1000 × 0.75 = 750.
Answer:
its already simplest form, if you mean fractions, then the answer is 1 27/100
Step-by-step explanation:
Answer:
1200
Step-by-step explanation:
The number who drink coffee is 3/4 of 8000, so ...
... (3/4)×8000 = 6000.
Of those, 1/5 add cream, so the number of coffee drinkers who add cream to their coffee is ...
... (1/5)×6000 = 1200.
_____
<em>Alternate solutions</em>
We have computed ...
... (1/5)×((3/4)×8000) = 1200
Since multiplication is associative, you can multiply the fractions first, if you wish:
... ((1/5)×(3/4))×8000 = (3/20)×8000
... = 24000/20 = 1200
or
... = 3×(8000/20) = 3×400 = 1200
