Answer:
b) 1.3 units
b) 22.61° East of North
Step-by-step explanation:


Magnitude of vector AB is 1.3 units

The direction of vector AB is 22.61° East of North
By the way the arrow is pointing?
It is given that the mean is 79.1 inches and standard deviation is 3.0 inches so it follows:

So the value from 75 to 81 is given by:

Use the table or a software to get the probability values and substitute to get the probability value as:
The probability is 0.6509.
15 and 21. From 1 to 3 is plus 2 and from 3 to 6 is plus 3 and from 6 to 10 is plus 4 and so on