Home / 827.64-1,240.56-643.68

Finding the Fourth Proportional to 827.64, 1,240.56 and 643.68

Calculator

Solution

The fourth proportional to 827.64, 1,240.56 and 643.68 is: 964.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    827.64 : 1,240.56 = 643.68 : x
  2. Step 2: Convert to fraction form
    827.64/1,240.56 = 643.68/x
  3. Step 3: Cross multiply
    827.64x = 1,240.56 × 643.68
  4. Step 4: Simplify right side
    827.64x = 798,523.66
  5. Step 5: Solve for x
    x = 798,523.66/827.64
  6. Step 6: Final answer
    x = 964.82

Related Problems

Find fourth proportional to 413.82, 620.28 and 321.84
Half scale
Find fourth proportional to 1,655.28, 2,481.12 and 1,287.36
Double scale
Find fourth proportional to 828.64, 1,242.06 and 644.68
Similar ratio
Find fourth proportional to 1,241.46, 1,860.84 and 965.52
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.