1. ## Probabilities

A survey revealed that 21.5% of the households had no checking account, 66.9% had regular checking accounts, and 11.6% had NOW accounts. Of those households with no checking account 40% had savings accounts. Of the households with regular checking accounts 71.6% had a savings account. Of the households with NOW accounts 79.3% had savings accounts.
The probability that a randomly selected household with a savings account has no checking account is:

2. Originally Posted by jax760
a survey revealed that 21.5% of the households had no checking account, 66.9% had regular checking accounts, and 11.6% had now accounts. Of those households with no checking account 40% had savings accounts. Of the households with regular checking accounts 71.6% had a savings account. Of the households with now accounts 79.3% had savings accounts.
The probability that a randomly selected household with a savings account has no checking account is:

21.5%*40%

3. thats not the right answer.

4. Originally Posted by jax760
A survey revealed that 21.5% of the households had no checking account, 66.9% had regular checking accounts, and 11.6% had NOW accounts. Of those households with no checking account 40% had savings accounts. Of the households with regular checking accounts 71.6% had a savings account. Of the households with NOW accounts 79.3% had savings accounts.
The probability that a randomly selected household with a savings account has no checking account is:
You need the concept of conditional probability:

Pr(no checking account | savings account) = Pr(no checking account and savings account)/Pr(Savings account) = [(0.4)(0.215)]/(answer to the question asked in http://www.mathhelpforum.com/math-he...abilities.html) = ....