For item numbers 18 to 20, consider the following problem: A total of ten vehicles were caught over speeding along Mac Arthur highway in a day. The speeds of each vehicle are recorded as follows: 45 42 50 48 41 45 60 54 48 56.

18. Find the mean of the over speeding data.

19. What is the value of 2 2 ( )

x x - ?- ?

20. What is the sample variance of the over speeding data?

21. What is the sample standard deviation of the over speeding

data?

22. Enumerate the characteristic of a normal curve.

23. The number of faculty and the number of students are shown

for a random selection of small colleges in Davao City. Determine if there is a

significant relationship between the two variables and discuss the result.

Faculty (X): 99 110 113 116 138 174 220

Students (Y): 1353 1290 1091 1213 1384 1283 2075