Since <em>X</em> follows a binomial distribution, its mean and variance are
<em>np</em> = 3
<em>np</em> (1 - <em>p</em>) = 2
Substitute <em>np</em> = 3 in to the second equation to solve for <em>p</em> :
3 (1 - <em>p</em>) = 2
1 - <em>p</em> = 2/3
<em>p</em> = 1/3
Solve for <em>n</em> :
<em>n</em> (1/3) = 3
<em>n</em> = 9
Answer:
Sara bought 5 6 penny nails and 3 10 penny nails
Step-by-step explanation:
Answer:
2 2/3 or 24/9
Step-by-step explanation:
3 2/9 - 5/9 = 24/9 = 2 6/9
3*9+2 = 29/9
29/9 - 5/9 = 2 6/9
2 6/9 turns into 2 2/3
2 2/3 is equal to 24/9
5 times the Sum of 3 and 4, then subtract 4