Answer:
The 80% confidence interval for difference between two means is (0.85, 1.55).
Step-by-step explanation:
The (1 - <em>α</em>) % confidence interval for difference between two means is:

Given:

Confidence level = 80%

*Use a <em>t</em>-table for the critical value.
Compute the 80% confidence interval for difference between two means as follows:

Thus, the 80% confidence interval for difference between two means is (0.85, 1.55).
I think the mean of variable a is 4
Part A:
Given that Nicholas's school is located at point (3, 2) and that the post office is located at point (-2, -2), then the distance between Nicholas's school and the post office is given by:

Part B:
If Nicholas is located at point (– 3 , 2), the distance to get to the grocery store located at point (1,-1) is given by:
Answer:
Cartesian Coordinate System
• Also called
rectangular coordinate
system
• x- and y- axes intersect
at the origin
• Points are labeled (x,y)
Polar Coordinate System
– Origin and reference
line are noted
– Point is distance r from
the origin in the
direction of angle θ,
ccw from reference
line
– Points are labeled (r,θ)
Cartesian to Polar Coordinates
• r is the hypotenuse and θ
an angle
θ must be ccw from
positive x axis for these
equations to be vali
Step-by-step explanation: