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Finding the Fourth Proportional to 653.12, 900.78 and 391.10

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Solution

The fourth proportional to 653.12, 900.78 and 391.10 is: 539.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.12 : 900.78 = 391.10 : x
  2. Step 2: Convert to fraction form
    653.12/900.78 = 391.10/x
  3. Step 3: Cross multiply
    653.12x = 900.78 × 391.10
  4. Step 4: Simplify right side
    653.12x = 352,295.06
  5. Step 5: Solve for x
    x = 352,295.06/653.12
  6. Step 6: Final answer
    x = 539.40

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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.