Home / 970.80-1,339.92-621.60

Finding the Fourth Proportional to 970.80, 1,339.92 and 621.60

Calculator

Solution

The fourth proportional to 970.80, 1,339.92 and 621.60 is: 857.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    970.80 : 1,339.92 = 621.60 : x
  2. Step 2: Convert to fraction form
    970.80/1,339.92 = 621.60/x
  3. Step 3: Cross multiply
    970.80x = 1,339.92 × 621.60
  4. Step 4: Simplify right side
    970.80x = 832,894.27
  5. Step 5: Solve for x
    x = 832,894.27/970.80
  6. Step 6: Final answer
    x = 857.95

Related Problems

Find fourth proportional to 485.40, 669.96 and 310.80
Half scale
Find fourth proportional to 1,941.60, 2,679.84 and 1,243.20
Double scale
Find fourth proportional to 971.80, 1,341.30 and 622.60
Similar ratio
Find fourth proportional to 1,456.20, 2,009.88 and 932.40
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.