Home / 640.80-962-611.38

Finding the Fourth Proportional to 640.80, 962 and 611.38

Calculator

Solution

The fourth proportional to 640.80, 962 and 611.38 is: 917.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.80 : 962 = 611.38 : x
  2. Step 2: Convert to fraction form
    640.80/962 = 611.38/x
  3. Step 3: Cross multiply
    640.80x = 962 × 611.38
  4. Step 4: Simplify right side
    640.80x = 588,147.56
  5. Step 5: Solve for x
    x = 588,147.56/640.80
  6. Step 6: Final answer
    x = 917.83

Related Problems

Find fourth proportional to 320.40, 481 and 305.69
Half scale
Find fourth proportional to 1,281.60, 1,924 and 1,222.76
Double scale
Find fourth proportional to 641.80, 963.50 and 612.38
Similar ratio
Find fourth proportional to 961.20, 1,443 and 917.07
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.