Four friends agree to save money for a graduation road trip. They decide that
2 answers:
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Answer:
26.11% of women in the United States will wear a size 6 or smaller
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
In the United States, a woman's shoe size of 6 fits feet that are 22.4 centimeters long. What percentage of women in the United States will wear a size 6 or smaller?
This is the pvalue of Z when X = 22.4. So
has a pvalue of 0.2611
26.11% of women in the United States will wear a size 6 or smaller
Answer:
Step-by-step explanation:
Given is the probability distribution of a random variable X
X 4 5 6 7 Total
P 0.2 0.4 0.3 0.1 1
x*p 0.8 2 1.8 0.7 5.3
x^2*p 3.2 10 10.8 4.9 28.9
a) E(X) = Mean of X = sum of xp = 5.3
Std dev = square root of variance = 0.9
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b) For sample mean we have
Mean = 5.3
Variance = var(x)/n =
c)