HOMEWORK 3 - FISH SIMULATION

FIRST PART

This sample lists the ages of Baruch students from last summer's ecology class.

Sample data: 25, 19, 23, 22, 30, 19, 22, 31, 32, 22, 30, 21, 20, 28, 24, 27, 32, 21 Calculate the following. INCLUDE UNITS!

1. sample size - n

2. Mean, mode, median

3. Range

4. Sum of squares, variance, standard deviation

5. 95% Confidence interval

6. Interpret Confidence interval, what does it mean?

7. If the true mean age of Baruch ecology students is 23, has your 95% CI captured it?

SECOND PART

On the course website for this lab, follow the instructions under the Virtual Fish Sampling heading and complete simulations 1 & 2 (Simulation 1: Mean & variation, Simulation 2: 95% confidence intervals).

Take notes and keep the answers for your records and understanding.

FOR THE HOMEWORK

Default setting for the parameters. Set the model parameters to the following values before each experiment:

N = 10

= 100

= 30

Observe what happens to the length/width of the Confidence Interval (CI) when you take repeated samples and change 1 variable.

For each of the three conditions below answer whether the CI became wider or narrower? Take an image of the results and paste it to include it with each answer. First, set the values to the default noted above, then change the one variable specified in the question.

Does the CI became wider or narrower, if you change:

a) sample size (n) from 10 to 40? (Set values back to the defaults; change sample size (n) back to 10)

b. confidence level from 95% and 99%? (Set values back to the defaults; change confidence level back to 95%)

c. population mean () from 100 to 150? (Set values back to the defaults; back to 100)

d. standard deviation () from 30 to 10?

DON'T FORGET TO INCLUDE IMAGES WITH YOUR ANSWERS!