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Finding the Fourth Proportional to 840.16, 1,259.14 and 429.40

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Solution

The fourth proportional to 840.16, 1,259.14 and 429.40 is: 643.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.16 : 1,259.14 = 429.40 : x
  2. Step 2: Convert to fraction form
    840.16/1,259.14 = 429.40/x
  3. Step 3: Cross multiply
    840.16x = 1,259.14 × 429.40
  4. Step 4: Simplify right side
    840.16x = 540,674.72
  5. Step 5: Solve for x
    x = 540,674.72/840.16
  6. Step 6: Final answer
    x = 643.54

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1.5x scale

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.