Measures of Dispersion - Jamb Mathematics Past Questions and Answers

Question 11:

• JAMB 1978

If y = 2x² + 9x - 35. Find the range of values for which y < 0.

A. 7 < x < \(\frac{5}{2}\)
B. -5 < 7 < x
C. -7 < x < 5
D. -7 < x < \(\frac{5}{2}\)

Question 12:

• JAMB 1984

The cumulative frequency function of the data below is given below by the equation y = cf(x). What is cf(5)?
\(\begin{array}{c|c} Score(n) & Frequency(f)\\\hline 3 & 30\\ 4 & 32\\ 5 & 30\\ 6 & 35\\8 & 20 \end{array}\)

A. 30
B. 32
C. 55
D. 62
E. 92

Question 13:

• JAMB 1992

If the scores of 3 students in a test are 5, 6 and 7, find the standard deviation of their scores

A. \(\frac{2}{3}\)
B. \(\frac{2}{3}\sqrt{3}\)
C. \(\sqrt{\frac{2}{3}}\)
D. \(\sqrt{\frac{3}{2}}\)

Question 14:

• JAMB 1993

Calculate the standard deviation of the following data: 7, 8, 9, 10, 11, 12, 13.

A. 2
B. 4
C. 10
D. 11

Question 15:

• JAMB 1994

Find the mean deviation of the set of numbers 4, 5, 9

A. Zero
B. 2
C. 5
D. 6