Finding the Fourth Proportional to 100.76, 139.05 and 79.09
Calculator
Solution
The fourth proportional to 100.76, 139.05 and 79.09 is: 109.15
Step by Step Solution
- Step 1: Write the proportion equation
100.76 : 139.05 = 79.09 : x - Step 2: Convert to fraction form
100.76/139.05 = 79.09/x - Step 3: Cross multiply
100.76x = 139.05 × 79.09 - Step 4: Simplify right side
100.76x = 10,997.12 - Step 5: Solve for x
x = 10,997.12/100.76 - Step 6: Final answer
x = 109.15
Related Problems
Find fourth proportional to 50.38, 69.53 and 39.54
Half scale
Find fourth proportional to 201.51, 278.10 and 158.18
Double scale
Find fourth proportional to 101.76, 140.43 and 80.09
Similar ratio
Find fourth proportional to 151.13, 208.58 and 118.63
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.