Home / 1,370.12-1,890.74-780.64

Finding the Fourth Proportional to 1,370.12, 1,890.74 and 780.64

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Solution

The fourth proportional to 1,370.12, 1,890.74 and 780.64 is: 1,077.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,370.12 : 1,890.74 = 780.64 : x
  2. Step 2: Convert to fraction form
    1,370.12/1,890.74 = 780.64/x
  3. Step 3: Cross multiply
    1,370.12x = 1,890.74 × 780.64
  4. Step 4: Simplify right side
    1,370.12x = 1,475,977.82
  5. Step 5: Solve for x
    x = 1,475,977.82/1,370.12
  6. Step 6: Final answer
    x = 1,077.27

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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.