Finding the Fourth Proportional to 128,979.56, 177,991.81 and 72,390.94
Calculator
Solution
The fourth proportional to 128,979.56, 177,991.81 and 72,390.94 is: 99,899.50
Step by Step Solution
- Step 1: Write the proportion equation
128,979.56 : 177,991.81 = 72,390.94 : x - Step 2: Convert to fraction form
128,979.56/177,991.81 = 72,390.94/x - Step 3: Cross multiply
128,979.56x = 177,991.81 × 72,390.94 - Step 4: Simplify right side
128,979.56x = 12,884,993,812.24 - Step 5: Solve for x
x = 12,884,993,812.24/128,979.56 - Step 6: Final answer
x = 99,899.50
Related Problems
Find fourth proportional to 64,489.78, 88,995.90 and 36,195.47
Half scale
Find fourth proportional to 257,959.13, 355,983.62 and 144,781.88
Double scale
Find fourth proportional to 128,980.56, 177,993.19 and 72,391.94
Similar ratio
Find fourth proportional to 193,469.34, 266,987.71 and 108,586.41
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.