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Finding the Fourth Proportional to 619.99, 856.10 and 387.19

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Solution

The fourth proportional to 619.99, 856.10 and 387.19 is: 534.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.99 : 856.10 = 387.19 : x
  2. Step 2: Convert to fraction form
    619.99/856.10 = 387.19/x
  3. Step 3: Cross multiply
    619.99x = 856.10 × 387.19
  4. Step 4: Simplify right side
    619.99x = 331,471.42
  5. Step 5: Solve for x
    x = 331,471.42/619.99
  6. Step 6: Final answer
    x = 534.64

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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.