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Finding the Fourth Proportional to 1,312.40, 1,811.23 and 840.71

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Solution

The fourth proportional to 1,312.40, 1,811.23 and 840.71 is: 1,160.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,312.40 : 1,811.23 = 840.71 : x
  2. Step 2: Convert to fraction form
    1,312.40/1,811.23 = 840.71/x
  3. Step 3: Cross multiply
    1,312.40x = 1,811.23 × 840.71
  4. Step 4: Simplify right side
    1,312.40x = 1,522,721.60
  5. Step 5: Solve for x
    x = 1,522,721.60/1,312.40
  6. Step 6: Final answer
    x = 1,160.26

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1.5x scale

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.