Answer:
And we are 9% confidence that the true mean for the difference of the population means is given by:
Step-by-step explanation:
For this problem we have the following data given:
represent the sample mean for one of the departments
represent the sample mean for the other department
represent the sample size for the first group
represent the sample size for the second group
represent the deviation for the first group
represent the deviation for the second group
Confidence interval
The confidence interval for the difference in the true means is given by:
The confidence given is 95% or 9.5, then the significance level is and . The degrees of freedom are given by:
And the critical value for this case is
And replacing we got:
And we are 9% confidence that the true mean for the difference of the population means is given by:
Answer:
The area under the curve that represents the percent of women whose heights are at least 64 inches is 0.5.
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, or the area under the curve representing values that are lower than x. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X, which is the same as the area under the curve representing values that are higher than x.
In this problem, we have that:
Find the area under the curve that represents the percent of women whose heights are at least 64 inches.
This is 1 subtracted by the pvalue of Z when X = 64.
has a pvalue of 0.5.
1 - 0.5 = 0.5
The area under the curve that represents the percent of women whose heights are at least 64 inches is 0.5.
Answer:
x=8
Step-by-step explanation:
2/3=x/12
3x=24
x=8
Im pretty sure the answer would be V=297cm³