Answer:
(a) The sample variance is 16.51
(a) The sample standard deviation is 4.06
Step-by-step explanation:
Given

Solving (a); The sample variance.
First, calculate the class midpoints.
This is the mean of the intervals.
i.e.





So, the table becomes:

Next, calculate the mean




Next, the sample variance is:

So, we have:



The sample standard deviation is:



Answer:
is the a. Perpendicular lines form 90° angles.
Answer: Store 2
Step-by-step explanation: sorry I don’t know how to explain.
Answer:
the rate of the first cyclist: 28km/h
the rate of the 2nd cyclist 28+4= 32km/h
Step-by-step explanation:
x= the rate of the first cyclist
x+4= the rate of the 2nd cyclist
after 4 hours: + the first cyclist travels 4x (km)
+ the 2nd cyclist travels 4(x+4) (km)
because the two cyclists are 240 km apart after 4 hours
=> 4x + 4(x+4) = 240 => x= 28
i hope it's useful forr u =)))