Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
That is z with a pvalue of , so Z = 1.28.
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Answer:
Step-by-step explanation:
The equation of the line is Slope-intercept form is:
Where "m" is the slope and "b" the y-intercept.
The slopes of perpendicular lines are negative reciprocal.
Then, if the slope of the first line is -3, the slope of the other line must be:
Substitute the point (3,4) into the equation and solve for b:
Then the equation of this line is: