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Finding the Fourth Proportional to 877.77, 1,316.64 and 390.81

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Solution

The fourth proportional to 877.77, 1,316.64 and 390.81 is: 586.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    877.77 : 1,316.64 = 390.81 : x
  2. Step 2: Convert to fraction form
    877.77/1,316.64 = 390.81/x
  3. Step 3: Cross multiply
    877.77x = 1,316.64 × 390.81
  4. Step 4: Simplify right side
    877.77x = 514,556.08
  5. Step 5: Solve for x
    x = 514,556.08/877.77
  6. Step 6: Final answer
    x = 586.21

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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.