# Math Help - probability

1. ## probability

i am having problems with those 2 kestions...

1. in order to verify the accuracy of their financial accounts, companies use auditors on a regular basis to verify accouting entries. the company's employees make erroneous entries 5% of the time. Suppose that an auditor checks three entries.
Find the probability distribution for Y, the number of errors detected by the auditor.

2. A heavy-equipment salesperson can contact either one or two customers per day with probability 1/3 and 2/3 respectively. each contact will result in either no sale or a sale of 50 000$, with probability 0.9 and 0.1 respectively. give the probability distribution for daily sales. find the mean and the standard deviation of the daily sales. 2. Originally Posted by calculator101 i am having problems with those 2 kestions... 1. in order to verify the accuracy of their financial accounts, companies use auditors on a regular basis to verify accouting entries. the company's employees make erroneous entries 5% of the time. Suppose that an auditor checks three entries. Find the probability distribution for Y, the number of errors detected by the auditor. Mr F says: See post #3 here: http://www.mathhelpforum.com/math-he...variables.html 2. A heavy-equipment salesperson can contact either one or two customers per day with probability 1/3 and 2/3 respectively. each contact will result in either no sale or a sale of 50 000$, with probability 0.9 and 0.1 respectively. give the probability distribution for daily sales. find the mean and the standard deviation of the daily sales.