Chau bought 28 pounds of flour for $12. How many dollars did he pay per pound of flour?
1 answer:
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Answer:
Jennifer's height is 63.7 inches.
Step-by-step explanation:
Let <em>X</em> = heights of adult women in the United States.
The random variable <em>X</em> is normally distributed with mean, <em>μ</em> = 65 inches and standard deviation <em>σ</em> = 2.4 inches.
To compute the probability of a normal random variable we first need to convert the raw score to a standardized score or <em>z</em>-score.
The standardized score of a raw score <em>X</em> is:
These standardized scores follows a normal distribution with mean 0 and variance 1.
It is provided that Jennifer is taller than 70% of the population of U.S. women.
Let Jennifer's height be denoted by <em>x</em>.
Then according to the information given:
P (X > x) = 0.70
1 - P (X < x) = 0.70
P (X < x) = 0.30
⇒ P (Z < z) = 0.30
The <em>z</em>-score related to the probability above is:
<em>z</em> = -0.5244
*Use a <em>z</em>-table.
Compute the value of <em>x</em> as follows:
Thus, Jennifer's height is 63.7 inches.
Answer:
B. 68%.
Step-by-step explanation:
We have been given that driving times for students' commute to school is normally distributed, with a mean time of 14 minutes and a standard deviation of 3 minutes.
First of all, we will find z-score of 11 and 17 using z-score formula.
We know that z-score tells us a data point is how many standard deviations above or below mean.
Our z-score -1 and 1 represent that 11 and 17 lie within one standard deviation of the mean.
By empirical rule 68% data lies with in one standard deviation of the mean, therefore, option B is the correct choice.