9: What is the probability of beef tips being the preferred new menu item?
To find the probability of a customer preferring beef tips over the other menu items, divide the quantity of customers that preferred beef tips over the total number of customers that participated in the survey:
28 / (42 + 28 + 30) = 28/100 = 28%
There is a 28% chance that beef tips is the new preferred menu item.
11: Out of a similar group of 375 customers, predict how many more customers will prefer chicken carbonara to shrimp scampi.
There are 100 customers that participated in the pre-existing survey. A grand total of 375 participants in a similar survey would mean that each food's preference would grow in a similar fashion.
100 * 3.75 = 375
You can then multiply each response group by 3.75 to find how many people prefer chicken carbonara and shrimp scampi.
42 * 3.75 = 157.5
30 * 3.75 = 112.5
Then, subtract the quantities to find out how many more people prefer chicken to shrimp.
157.5 - 112.5 = 45 people.
13: Predict the number of times that Giorgianna's name will be drawn in 32 weeks. Round to the nearest whole number.
There are five people in the group, and one is chosen as the team leader every week. 1 divided by 5 is .2, so the probability of being chosen as team leader is 20%.
You can multiply 0.2 by 32 to represent how many times the experiment will be run. The product is 6.4 times, so Giorgianna's name will likely be drawn 6 times within 32 weeks.