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Finding the Fourth Proportional to 421.36, 577.94 and 386.80

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Solution

The fourth proportional to 421.36, 577.94 and 386.80 is: 530.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.36 : 577.94 = 386.80 : x
  2. Step 2: Convert to fraction form
    421.36/577.94 = 386.80/x
  3. Step 3: Cross multiply
    421.36x = 577.94 × 386.80
  4. Step 4: Simplify right side
    421.36x = 223,547.19
  5. Step 5: Solve for x
    x = 223,547.19/421.36
  6. Step 6: Final answer
    x = 530.54

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.