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Finding the Fourth Proportional to 783.66, 1,081.70 and 485.01

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Solution

The fourth proportional to 783.66, 1,081.70 and 485.01 is: 669.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.66 : 1,081.70 = 485.01 : x
  2. Step 2: Convert to fraction form
    783.66/1,081.70 = 485.01/x
  3. Step 3: Cross multiply
    783.66x = 1,081.70 × 485.01
  4. Step 4: Simplify right side
    783.66x = 524,632.89
  5. Step 5: Solve for x
    x = 524,632.89/783.66
  6. Step 6: Final answer
    x = 669.46

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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.