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Finding the Fourth Proportional to 611.40, 916.56 and 287.40

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Solution

The fourth proportional to 611.40, 916.56 and 287.40 is: 430.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.40 : 916.56 = 287.40 : x
  2. Step 2: Convert to fraction form
    611.40/916.56 = 287.40/x
  3. Step 3: Cross multiply
    611.40x = 916.56 × 287.40
  4. Step 4: Simplify right side
    611.40x = 263,419.34
  5. Step 5: Solve for x
    x = 263,419.34/611.40
  6. Step 6: Final answer
    x = 430.85

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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.