Question

1. A company is testing a new energy drink. Volunteers are asked to rate their energy one hour

after consuming a beverage. Unknown to them, some volunteers are given the real energy
drink and some are given a placebo-a drink that looks and tastes the same, but does not have
the energy-producing ingredients. Show your work using the following list of random digits to
assign each participant listed either the real drink or the placebo.
69429 86140 11625 87049 23167
Volunteer
Abby
Barry
87524 24575 87254 97801 82231
Callie
Dion
Ernie
Falco
Garrett
Hallie
Indigo
Jaylene
Real or Placebo
2. The local water authority has received complaints of high levels of iron in the drinking water.
They decide to randomly select 20 houses from each subdivision of 100 houses to visit and test
their water. Describe how to use random numbers to select the 20 houses in each division.
3. A couple is willing to have as many children as necessary to have two girls.
a) Describe a simulation that can be performed to estimate the average number of children
required to have two girls.

Answer 1

1. To assign each volunteer either the real drink or the placebo, we can use the following method:

- Assign the first five volunteers (Abby, Barry, Callie, Dion, and Ernie) to the first five digits in the list (6, 9, 4, 2, 9).
- If the digit is even, assign the volunteer the real drink; if it is odd, assign the volunteer the placebo.
- Repeat this process for the remaining volunteers (Falco, Garrett, Hallie, Indigo, and Jaylene) using the next five digits in the list (8, 6, 1, 4, 0).

Here is the assignment:

Volunteer | Real or Placebo
----------|----------------
Abby | Real
Barry | Real
Callie | Placebo
Dion | Real
Ernie | Placebo
Falco | Real
Garrett | Real
Hallie | Real
Indigo | Placebo
Jaylene | Placebo


2. To select the 20 houses in each division, we can use the following method:

- Assign each house in the subdivision a number from 01 to 100.
- Use a random number generator to generate 20 random numbers between 01 and 100.
- Visit the houses corresponding to the 20 numbers generated.

Repeat this process for each subdivision.

3. One way to simulate the average number of children required to have two girls is to use the following method:

- Assign a value of 0 to a counter variable.
- Repeat the following steps until two girls are born:
- Use a random number generator to generate a number between 0 and 1.
- If the number is less than 0.5, add 1 to the counter variable (representing a boy); otherwise, add 2 to the counter variable (representing a girl).
- Record the value of the counter variable.
- Repeat this process a large number of times (e.g., 10,000).
- Calculate the average value of the counter variable across all simulations. This will give an estimate of the average number of children required to have two girls.