x+2 > 10 solves to x > 8 after we subtract 2 from both sides
So set A is the set of real numbers that are larger than 8. The value 8 itself is not in set A. The same can be said about 5 as well.
Set B is the set of values that are larger than 5 since 2x > 10 turns into x > 5 after dividing both sides by 2. The value x = 5 is not in set B since x > 5 would turn into 5 > 5 which is false. The values x = 6, x = 8, and x = 9 are in set B.
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Summarizing everything, we can say...
5 is not in set A. True
5 is in set B. False
6 is in set A. False
6 is not in set B. False
8 is not in set A. True
8 is in set B. True
9 is in set A. True
9 is not in set B. False
To solve this, we use the z test.
The formula:
z = (x – u) / s
where x is sample value = 20, u is the mean = 15, and s is
the standard deviation = 2.5
z = (20 – 15) / 2.5
z = 2
Since we are looking for values greater than 20, this is
right tailed test. We use the standard distribution tables to find for P.
P = 0.0228
Therefore:
number of students = 100 * 0.0228 = 2.28
<span>2 to 3 students will get greater than 20 measurement</span>
Answer:
this should be right if not comment and I'll relook it.
FOIL Method.
You will get the same answer x^2+ 7x- 18