Home / 654.90-981.36-438.09

Finding the Fourth Proportional to 654.90, 981.36 and 438.09

Calculator

Solution

The fourth proportional to 654.90, 981.36 and 438.09 is: 656.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    654.90 : 981.36 = 438.09 : x
  2. Step 2: Convert to fraction form
    654.90/981.36 = 438.09/x
  3. Step 3: Cross multiply
    654.90x = 981.36 × 438.09
  4. Step 4: Simplify right side
    654.90x = 429,924.00
  5. Step 5: Solve for x
    x = 429,924.00/654.90
  6. Step 6: Final answer
    x = 656.47

Related Problems

Find fourth proportional to 327.45, 490.68 and 219.05
Half scale
Find fourth proportional to 1,309.80, 1,962.72 and 876.18
Double scale
Find fourth proportional to 655.90, 982.86 and 439.09
Similar ratio
Find fourth proportional to 982.35, 1,472.04 and 657.14
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.