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Finding the Fourth Proportional to 985, 1,359.48 and 690.72

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Solution

The fourth proportional to 985, 1,359.48 and 690.72 is: 953.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    985 : 1,359.48 = 690.72 : x
  2. Step 2: Convert to fraction form
    985/1,359.48 = 690.72/x
  3. Step 3: Cross multiply
    985x = 1,359.48 × 690.72
  4. Step 4: Simplify right side
    985x = 939,020.03
  5. Step 5: Solve for x
    x = 939,020.03/985
  6. Step 6: Final answer
    x = 953.32

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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.