A., B., C., D., are NOT true. I think this is a trick question. Lol
Answer: chicken $8, duck $5
Explanation:
x - the cost of a chicken
y - the cost of a duck
he sold 50 chickens and 30 ducks for $550: 50x + 30y = 550
he sold 44 chickens and 36 ducks for $532: 44x + 36y = 532
50x + 30y = 550 divide by 10
44x + 36y = 550 divide by 4
______________
50x/10 + 30y/10 = 550/10
44x/4 + 36y/4 = 532/4
______________
5x + 3y = 55
Multiply by (-3)
11x + 9y = 133
______________
5x * (-3) + 3y * (-3) = 55 * (-3)
11x + 9y = 133
______________
-15x - 9y = -165
11x + 9y = 133
______________
Sum up:
-4x + 0y = -32
-4x = -32
x = -32/-4
x = 8
Since 5x + 3y = 55 and x = 8, then:
5 * 8 + 3y = 55
40 + 3y = 55
3y = 55 - 40
3y = 15
y = 15/3
y = 5
D.3.1 is the greatest value from the list.
Answer:
A) 99.7% of people have an IQ between 64 and 136.
B) 5% of people have an IQ score less than 76 or greater than 124.
C) 16% of people have an IQ score greater than 112.
Step-by-step explanation:
The Empirical Rule tells us that, in a normal or 'bell-shaped' distribution, 68% of the data is one standard deviation from the mean, 95% of the data is two standard deviations from the mean, and 99.7% of the data is three standard deviations from the mean.
A) 64 and 136 are 3 standard deviations away from the mean, so 99.7% of people have an IQ between 64 and 136.
B) 76 and 124 are 2 standard devations away from the mean, but the answer is asking what percentage is not between them. 100% - 95% gives us 5%.
C) 112 is one standard deviation away from the mean. If we want to find the percentage greater, then we can do 100% - 50% (as 112 is to the left of the mean), then we can take half of 68 to get 34%, and after subtracting 50% and 34% from the 100%, we get 16%.