Home / 885.60-1,221.60-688.80

Finding the Fourth Proportional to 885.60, 1,221.60 and 688.80

Calculator

Solution

The fourth proportional to 885.60, 1,221.60 and 688.80 is: 950.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    885.60 : 1,221.60 = 688.80 : x
  2. Step 2: Convert to fraction form
    885.60/1,221.60 = 688.80/x
  3. Step 3: Cross multiply
    885.60x = 1,221.60 × 688.80
  4. Step 4: Simplify right side
    885.60x = 841,438.08
  5. Step 5: Solve for x
    x = 841,438.08/885.60
  6. Step 6: Final answer
    x = 950.13

Related Problems

Find fourth proportional to 442.80, 610.80 and 344.40
Half scale
Find fourth proportional to 1,771.20, 2,443.20 and 1,377.60
Double scale
Find fourth proportional to 886.60, 1,222.98 and 689.80
Similar ratio
Find fourth proportional to 1,328.40, 1,832.40 and 1,033.20
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.