Home / 1,215.38-1,820.43-890

Finding the Fourth Proportional to 1,215.38, 1,820.43 and 890

Calculator

Solution

The fourth proportional to 1,215.38, 1,820.43 and 890 is: 1,333.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,215.38 : 1,820.43 = 890 : x
  2. Step 2: Convert to fraction form
    1,215.38/1,820.43 = 890/x
  3. Step 3: Cross multiply
    1,215.38x = 1,820.43 × 890
  4. Step 4: Simplify right side
    1,215.38x = 1,620,182.70
  5. Step 5: Solve for x
    x = 1,620,182.70/1,215.38
  6. Step 6: Final answer
    x = 1,333.07

Related Problems

Find fourth proportional to 607.69, 910.22 and 445
Half scale
Find fourth proportional to 2,430.76, 3,640.86 and 1,780
Double scale
Find fourth proportional to 1,216.38, 1,821.93 and 891
Similar ratio
Find fourth proportional to 1,823.07, 2,730.65 and 1,335
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.