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Finding the Fourth Proportional to 989.85, 1,485.01 and 340.57

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Solution

The fourth proportional to 989.85, 1,485.01 and 340.57 is: 510.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.85 : 1,485.01 = 340.57 : x
  2. Step 2: Convert to fraction form
    989.85/1,485.01 = 340.57/x
  3. Step 3: Cross multiply
    989.85x = 1,485.01 × 340.57
  4. Step 4: Simplify right side
    989.85x = 505,742.43
  5. Step 5: Solve for x
    x = 505,742.43/989.85
  6. Step 6: Final answer
    x = 510.93

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Double scale
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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.