Home / 810.40-1,215-672.88

Finding the Fourth Proportional to 810.40, 1,215 and 672.88

Calculator

Solution

The fourth proportional to 810.40, 1,215 and 672.88 is: 1,008.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.40 : 1,215 = 672.88 : x
  2. Step 2: Convert to fraction form
    810.40/1,215 = 672.88/x
  3. Step 3: Cross multiply
    810.40x = 1,215 × 672.88
  4. Step 4: Simplify right side
    810.40x = 817,549.20
  5. Step 5: Solve for x
    x = 817,549.20/810.40
  6. Step 6: Final answer
    x = 1,008.82

Related Problems

Find fourth proportional to 405.20, 607.50 and 336.44
Half scale
Find fourth proportional to 1,620.80, 2,430 and 1,345.76
Double scale
Find fourth proportional to 811.40, 1,216.50 and 673.88
Similar ratio
Find fourth proportional to 1,215.60, 1,822.50 and 1,009.32
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.