Using the normal distribution, it is found that a production worker has to make $542.64 a week to be in the top 30% of wage earners.
<h3>Normal Probability Distribution</h3>
In a normal distribution with mean and standard deviation , the z-score of a measure X is given by:
- It 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, which is the percentile of X.
In this problem:
- The mean is of .
- The standard deviation is of .
- The lower bound of the top 30% is the 70th percentile, which is X when Z has a p-value of 0.7, so <u>X when Z = 0.84.</u>
A production worker has to make $542.64 a week to be in the top 30% of wage earners.
You can learn more about the normal distribution at brainly.com/question/24663213
Answer:
b. the sample standard deviation is used to estimate the population standard deviation.
Correct since that's the best approximation in order to use the t distribution to estimate the mean
Step-by-step explanation:
For this problem let's analyze the possible options:
a. the population has a mean of less than 30.
False since the mean can be any value and not makes sense
b. the sample standard deviation is used to estimate the population standard deviation.
Correct since that's the best approximation in order to use the t distribution to estimate the mean
c. the variance of the population is known.
False if the variance is know we can use the z distribution for the confidence interval and is not neccessary the t distribution
d. the mean of the population is unknown.
False we create the confidence interval since we don't know the true mean beacuse if we know the mean we don't need to create an interval
Answer:
B. first step
6/7x=7/8-1/2
c. second step
6/7x=7/8-4/8=3/8
d. and e are the same
x=3/8x7/6
Step-by-step explanation:
Percentage error is calculated by
Percentage error = (estimate-real)/real*100%=(115-82.5)/82.5*100%=28.26%
An over-estimate gives a positive error percent, and an underestimate gives a negative error.
Also, dividing by the real value makes it possible to have more than 100% error.
For example, if real cost is $50, and estimated cost is $150, then error percent is (150-50)/50*100%=200%!