probability

Question

Twelve of the 20 students in Mr. Skinner’s class brought lunch from home. Fourteen of the 21 students in Ms. Cho’s class brought lunch from home. Siloni is using two 15-section spinners to simulate randomly selecting students from each class and predicting whether they brought lunch from home or will buy lunch in the cafeteria.

If each spinner is divided into 15 congruent sectors, how does the spinner representing Mr. Skinner’s class differ from the spinner representing Ms. Cho’s class?

Answer 1

12/20 reduces to 4/5 --> 4/5 of 15 is 12.

So using the spinner to model Mr. Skinner's class,

an outcome of the select 12 sections of interest

represent, symbolize, and model a student bringing

lunch from home.

 

LIkewise, 14/21 reduces to 2/3 --> 2/3 of 15 is 10.

So using the spinner to model Ms. CHo's class, an

outcome of only 10 of the 15 sections of interest

represent, model, and symbolize a student 

who brings lunch from home.

 

The same can be done in MS Excel:   the function is =randBEtween( minVal, maxVal)

 

for example =randBetween(1,20) will model Mr. Skinner's class. A result of 12 or

less represents, model, simulates, and symbolizes a student who packed their lunch.

 

For Ms. Cho's class, the formula is =randBetween(1,21). The result of interest is 14 or less.