Question

Giving a test to a group of students, the grades and if they were a business major are summarized below. A | B | C | Total Business Majors 1216735 Non-business Majors 10 65 21 Tota 22 22 1256 If one student is chosen at random, find the probability that the student was business major AND got a "B". Give your answer as a fraction or decimal out to at least 4 places.

Answer 1

Solution :

	$\mathrm{A}$	$\mathrm{B}$	$\mathrm{C}$	$\mathrm{Total}$
$\mathrm{Business\:Majors}$	$\mathrm{12}$	$\mathrm{\bold{16}}$	$\mathrm{7}$	$\mathrm{35}$
$\mathrm{Non-business\:Majors}$	$\mathrm{10}$	$\mathrm{6}$	$\mathrm{5}$	$\mathrm{21}$
$\mathrm{Total}$	$\mathrm{22}$	$\mathrm{22}$	$\mathrm{12}$	$\mathrm{\bold{56}}$

$\mathrm{Total\:number\:of\:students\:=\:56}$

$\mathrm{There\:are\:\:16\:\:business\:major\:who\:got\:a\:"B"\:.}$

$\mathrm{Now,}$

$\mathrm{Probability\:that\:the\:student\:was\:business\:major\:AND\:got\:a\:"B"\::}$

$\mathrm{=\frac{16}{56}}$

$\mathrm{=\bold{0.2857}}$