Home / 898.60-1,347.90-321.40

Finding the Fourth Proportional to 898.60, 1,347.90 and 321.40

Calculator

Solution

The fourth proportional to 898.60, 1,347.90 and 321.40 is: 482.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.60 : 1,347.90 = 321.40 : x
  2. Step 2: Convert to fraction form
    898.60/1,347.90 = 321.40/x
  3. Step 3: Cross multiply
    898.60x = 1,347.90 × 321.40
  4. Step 4: Simplify right side
    898.60x = 433,215.06
  5. Step 5: Solve for x
    x = 433,215.06/898.60
  6. Step 6: Final answer
    x = 482.10

Related Problems

Find fourth proportional to 449.30, 673.95 and 160.70
Half scale
Find fourth proportional to 1,797.20, 2,695.80 and 642.80
Double scale
Find fourth proportional to 899.60, 1,349.40 and 322.40
Similar ratio
Find fourth proportional to 1,347.90, 2,021.85 and 482.10
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.