Home / 865.72-1,193.70-643.96

Finding the Fourth Proportional to 865.72, 1,193.70 and 643.96

Calculator

Solution

The fourth proportional to 865.72, 1,193.70 and 643.96 is: 887.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.72 : 1,193.70 = 643.96 : x
  2. Step 2: Convert to fraction form
    865.72/1,193.70 = 643.96/x
  3. Step 3: Cross multiply
    865.72x = 1,193.70 × 643.96
  4. Step 4: Simplify right side
    865.72x = 768,695.05
  5. Step 5: Solve for x
    x = 768,695.05/865.72
  6. Step 6: Final answer
    x = 887.93

Related Problems

Find fourth proportional to 432.86, 596.85 and 321.98
Half scale
Find fourth proportional to 1,731.44, 2,387.40 and 1,287.92
Double scale
Find fourth proportional to 866.72, 1,195.08 and 644.96
Similar ratio
Find fourth proportional to 1,298.58, 1,790.55 and 965.94
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.