Proportions - Defects

Apple manufactures iphones and checks some iphones for defects. Within the first five minutes of a work shift, an iphone is randomly selected from the completed iphones, and checked for defects. For the rest of the shift, every 10th iphone is checked for defects. On one shift, it is found that 300 out of 2,000 iphones have defects.

a. Based on these results, what is the probability of an iphone manufactured by the company being defective?

b. Estimate how many iphones out of 3,000 manufactured can be expected to be defective. What if 5,000 were manufactured?

Percents - Do want fries with that?

Yesterday, at Burger King where Dominique works, 60% of the customers ordered a burger. Show all work.



a. If 42% of the customers ordered a burger and fries, what is the probability that a customer who ordered a burger also ordered fries?



b. If 15% of the customers ordered a burger and onion rings, what is the probability that a customer ordered onion rings given that he/she ordered a burger?



c. If 36% of the customers ordered a burger and milkshake, what is the probability that a customer who ordered a burger also ordered a milkshake?

Sale Commission

Jennifer sells major appliances. She is paid a monthly salary of $1,600, plus a commission of 5% on the first $2,000 of monthly sales and 10% on the rest of her monthly sales over $2,000.

a. What is Jennifer's income for a month having sales of $5,938.50? Explain.

b. What if Jennifer worked at the same job but was paid a monthly salary of $1,000 plus a 15% commission on her monthly sales. Would she have paid more or less than the amount in part A for the same monthly sales? Explain.