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Finding the Fourth Proportional to 858.72, 1,280.79 and 729.66

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Solution

The fourth proportional to 858.72, 1,280.79 and 729.66 is: 1,088.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.72 : 1,280.79 = 729.66 : x
  2. Step 2: Convert to fraction form
    858.72/1,280.79 = 729.66/x
  3. Step 3: Cross multiply
    858.72x = 1,280.79 × 729.66
  4. Step 4: Simplify right side
    858.72x = 934,541.23
  5. Step 5: Solve for x
    x = 934,541.23/858.72
  6. Step 6: Final answer
    x = 1,088.30

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.