Home / 864.40-1,296.40-287.12

Finding the Fourth Proportional to 864.40, 1,296.40 and 287.12

Calculator

Solution

The fourth proportional to 864.40, 1,296.40 and 287.12 is: 430.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.40 : 1,296.40 = 287.12 : x
  2. Step 2: Convert to fraction form
    864.40/1,296.40 = 287.12/x
  3. Step 3: Cross multiply
    864.40x = 1,296.40 × 287.12
  4. Step 4: Simplify right side
    864.40x = 372,222.37
  5. Step 5: Solve for x
    x = 372,222.37/864.40
  6. Step 6: Final answer
    x = 430.61

Related Problems

Find fourth proportional to 432.20, 648.20 and 143.56
Half scale
Find fourth proportional to 1,728.80, 2,592.80 and 574.24
Double scale
Find fourth proportional to 865.40, 1,297.90 and 288.12
Similar ratio
Find fourth proportional to 1,296.60, 1,944.60 and 430.68
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.