SAT数学Problem Solving练习题(5)
- 2017年07月21日14:38 来源:互联网
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以下是小站SAT频道为大家整理了SAT数学Problem Solving练习题(5),供考生们参考,以下是详细内容。
Question #9: What is the value of the median of an equilateral triangle with all sides equal to 5?
(a) (5/2) · √3
(b) 5 · √3
(c) (5/2) · 3-3
(d) 5/2
(e) 5
Answer: The median divides the equilateral triangle in two right triangles. Conform to the Pythagorean theorem, wherein the sum of the squares of the two legs is equal to the square of the hypotenuse,
m2 + (5/2)2= 52
m2 = 52 - (5/2)2 = 52 - 52/4 = (3/4) · 52
m = (5/2) · √3.
Question #10: A parameter is measured during a scientific experiment and the results are -12, 4, -8, 10, 2, 2, 0, -4 and 2. The median and the average of these numbers are:
(a) median = 0, average = -4/9
(b) median = 0, average = 4/9
(c) median = 2, average = -4/9
(d) median = 2, average = 4/9
(e) median = 2, average = 2/9
Answer: You must arrange the numbers in order: -12, -8, -4, 0, 2, 2, 2, 4, and 10.
The median will be number in the middle of the row, that is 2.
The average will be (-12-8-4+0+2+2+2+4+10)/9 = -4/9.