Home / 1,221.40-1,821.29-1,172.80

Finding the Fourth Proportional to 1,221.40, 1,821.29 and 1,172.80

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Solution

The fourth proportional to 1,221.40, 1,821.29 and 1,172.80 is: 1,748.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,221.40 : 1,821.29 = 1,172.80 : x
  2. Step 2: Convert to fraction form
    1,221.40/1,821.29 = 1,172.80/x
  3. Step 3: Cross multiply
    1,221.40x = 1,821.29 × 1,172.80
  4. Step 4: Simplify right side
    1,221.40x = 2,136,008.91
  5. Step 5: Solve for x
    x = 2,136,008.91/1,221.40
  6. Step 6: Final answer
    x = 1,748.82

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.