Answer:
80
Step-by-step explanation:
89^2-39^2=6400, 6400=80^2
We have a line y = 1/3x -6
We want a line that is perpendicular to this line
Perpendicular lines have slopes that multiply to -1
1/3 * m = -1
3 * 1/3 *m = -1 * 3
m = -3
The slope of the perpendicular line is -3
y = mx+b where m is the slope and b is the y intercept
y = -3x+b
We have a point on the line ( 7 ,-23)
Substitute this point into the equation
-23 = -3(7)+b
-23 = -21+b
Add 21 to each side
-23+21 = -21+21+b
-2 = b
y = -3x-2
In slope intercept form, the line perpendicular passing through (7,-23) is
y = -3x-2
Answer:
The 95% confidence interval for the true population mean dog weight is between 62.46 ounces and 71.54 ounces.
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 
.
So it is z with a pvalue of 
, so 
Now, find 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 67 - 4.54 = 62.46 ounches.
The upper end of the interval is the sample mean added to M. So it is 67 + 4.54 = 71.54 ounces.
The 95% confidence interval for the true population mean dog weight is between 62.46 ounces and 71.54 ounces.
