Home / 1,369.12-2,053.68-821.20

Finding the Fourth Proportional to 1,369.12, 2,053.68 and 821.20

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Solution

The fourth proportional to 1,369.12, 2,053.68 and 821.20 is: 1,231.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,369.12 : 2,053.68 = 821.20 : x
  2. Step 2: Convert to fraction form
    1,369.12/2,053.68 = 821.20/x
  3. Step 3: Cross multiply
    1,369.12x = 2,053.68 × 821.20
  4. Step 4: Simplify right side
    1,369.12x = 1,686,482.02
  5. Step 5: Solve for x
    x = 1,686,482.02/1,369.12
  6. Step 6: Final answer
    x = 1,231.80

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1.5x scale

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.