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Finding the Fourth Proportional to 684.99, 945.38 and 390.35

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Solution

The fourth proportional to 684.99, 945.38 and 390.35 is: 538.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.99 : 945.38 = 390.35 : x
  2. Step 2: Convert to fraction form
    684.99/945.38 = 390.35/x
  3. Step 3: Cross multiply
    684.99x = 945.38 × 390.35
  4. Step 4: Simplify right side
    684.99x = 369,032.42
  5. Step 5: Solve for x
    x = 369,032.42/684.99
  6. Step 6: Final answer
    x = 538.74

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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.