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Finding the Fourth Proportional to 670.15, 924.78 and 390.39

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Solution

The fourth proportional to 670.15, 924.78 and 390.39 is: 538.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.15 : 924.78 = 390.39 : x
  2. Step 2: Convert to fraction form
    670.15/924.78 = 390.39/x
  3. Step 3: Cross multiply
    670.15x = 924.78 × 390.39
  4. Step 4: Simplify right side
    670.15x = 361,024.86
  5. Step 5: Solve for x
    x = 361,024.86/670.15
  6. Step 6: Final answer
    x = 538.72

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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.