Determine the probability of choosing a pair need help
1 answer:
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Answer:
Z scores between -0.995 and 0.995 bound the middle 68% of the area under the stanrard normal curve
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Middle 68%
Between the 50 - (68/2) = 16th percentile and the 50 + (68/2) = 84th percentile.
16th percentile:
X when Z has a pvalue of 0.16. So X when Z = -0.995
84th percentile:
X when Z has a pvalue of 0.84. So X when Z = 0.995.
Z scores between -0.995 and 0.995 bound the middle 68% of the area under the stanrard normal curve
Answer:
0.1527
Step-by-step explanation:
Given that a researcher wishes to conduct a study of the color preferences of new car buyers.
Suppose that 50% of this population prefers the color red
15 buyers are randomly selected
Let X be the no of buyers who prefer red.
X has exactly two outcomes red or non red.
Also each buyer is independent of the other
Hence X is binomial with p = 0.5 and n = 15
Required prob =The probability that exactly three-fifths of the buyers would prefer red
= P(X=9)
=
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