Home / 1,214.40-1,673.76-821.28

Finding the Fourth Proportional to 1,214.40, 1,673.76 and 821.28

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Solution

The fourth proportional to 1,214.40, 1,673.76 and 821.28 is: 1,131.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,214.40 : 1,673.76 = 821.28 : x
  2. Step 2: Convert to fraction form
    1,214.40/1,673.76 = 821.28/x
  3. Step 3: Cross multiply
    1,214.40x = 1,673.76 × 821.28
  4. Step 4: Simplify right side
    1,214.40x = 1,374,625.61
  5. Step 5: Solve for x
    x = 1,374,625.61/1,214.40
  6. Step 6: Final answer
    x = 1,131.94

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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.