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Finding the Fourth Proportional to 805.02, 1,207.95 and 420.30

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Solution

The fourth proportional to 805.02, 1,207.95 and 420.30 is: 630.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.02 : 1,207.95 = 420.30 : x
  2. Step 2: Convert to fraction form
    805.02/1,207.95 = 420.30/x
  3. Step 3: Cross multiply
    805.02x = 1,207.95 × 420.30
  4. Step 4: Simplify right side
    805.02x = 507,701.39
  5. Step 5: Solve for x
    x = 507,701.39/805.02
  6. Step 6: Final answer
    x = 630.67

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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.