DAT Math

• 1 in = 2.54 cm
• 1 mile = 5280 ft
• 1 kg = 2.2 lb
• Permutation: does order matter? yes

  • Repetition allowed: $n^r$
  • No repetition: $n!/(n-r)!$
• Combination: does order matter? no

  • Repetition allowed: $(r+n-1)!/r!(n-1)!$
  • No repetition: $n!/r!(n-r)!$
• Standard deviation:

  • 68% fall within 1 st dev
  • 95% fall within 2 st dev
  • 97.7 fall within 3 st dev
• log(1/x) = -log(x)
• In a deck of cards there are 52 cards, 13 in each suit. Each suit has a king, queen and a jack, the numbers 2-10, and an ace.
• Z-score = $x - mean/SD$
• $log_a(x)=$$b$is the same as $a^b=$$x$
• Volume of a sphere: 4/3 pi r^3
• The percent increase is given by (new - original)/original
• The inverse of a function means to switch the x and y values
• To convert from Fahrenheit to Celsius: (F - 32) x (5/9) = C