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:
1
Step-by-step explanation:
Remember that the slope intercept formula is:
y = mx + b
m is the slope
b is the y-intercept
If lines are parallel then they have the same slope (m)
This means that the slope of the line will be 3
:
y = 3x + b
Now we must find b
To do that you must plug in the point the line goes through in the x and y of the equation.
(-6, 3)
3 = 3(-6) + b
3 = -18 + b
21 = b
y = 3x + 21
Hope this helped!
~Just a girl in love with Shawn Mendes