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a science test, which is worth 100 points, consists of 24 questions. each question is worth either 3 points or 5 points. if x is
the number of 3-point questions and y is the number of 5-point questions, the system shown represents this situation.
x+y=24
3x + 5y = 100
what does the solution of this system indicate about the questions on the
the test contains 4 three-point questions and 20 five-point questions,
the test contains 10 three-point questions and 14 five-point questions.
the test contains 14 three-point questions and 10 five-point questions.
the test contains 20 three-point questions and 8 five-point questions
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the answer is a

step-by-step explanation:

66.666666667%

step-by-step explanation:

divide 150 by 100

divide 100 by 1.5

there you go!

decreased by 33.333333334%

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.