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Finding the Fourth Proportional to 1,223.40, 1,686.08 and 891.30

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Solution

The fourth proportional to 1,223.40, 1,686.08 and 891.30 is: 1,228.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,223.40 : 1,686.08 = 891.30 : x
  2. Step 2: Convert to fraction form
    1,223.40/1,686.08 = 891.30/x
  3. Step 3: Cross multiply
    1,223.40x = 1,686.08 × 891.30
  4. Step 4: Simplify right side
    1,223.40x = 1,502,803.10
  5. Step 5: Solve for x
    x = 1,502,803.10/1,223.40
  6. Step 6: Final answer
    x = 1,228.38

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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.