Question

Hi there,

I want to make an experiment that you can use a one sample z- test and interval on it. The project is a paper helicopter and we can make as many we like and then explain the process It should be dropped from a height and a weight like paperclip in the bottom to make fall. Please help me with this project.

1st: what is inference procedure and the variables you are

estimating

2nd: the experiment procedure, the condition and how we can prevent bias

3rd. what kind of difficulties I could have on making such an experiment.

Answer 1

This question can be answerd from many point of views. All the answers will be subjective in nature. I shall try to explain one scenario with the given condition. As the question says that it is required to perform a one sample z-test, the answers will be given from that perspective.

Case 1: Assumptions:

a) all the helicopters are made from identical papers, i.e., same element paper is being used to make the helicopters

b) same weight paper clip is attached to each of them

C) all of them are dropped from same height H

Now, assume we drop a totan of N helicopters.

Suppose our claim is the helicopters take an average time of T0 to reach ground from height H

then 1st question: here we are testing H0: T=T0

we are testing the mean time. we shall be estimating sample mean time and conduct our one sample z-test.

for conducting Z test it is assumed that variance is known. we shall take a random sample of n from N and perform this test.

2nd question: Procedure: Drop N helicopters, note the time of falling for each of them. then take a random sample of size n from those N observations. Here random variable is time to fall from height H.

calculate mean of these n samples.

Assume variance to be known.

find the value of test stat based on n samples.

test stat is given by: [Sqrt(n)*(x̅-T0)]/σ

compare the observed value of test statistic with Z table value to conclude.

Bias prevention: paper is of same material and clip attached is of same weight. because , if any of them vary between helicopters then bias will be introduced. for example, you make all helicopters with a certain paper but for making one, you are using more heavy paper, in this case bias will be introduced. similar for clip weight also. same weight clips will be required to prevent bias.

Note that, Air condition/Air pressure cant be controlled, those will be tackeled by the error part in the model.

3rd queston: Main difficulty is creating the environment. everything should be identical. Air pressure should be more or less same. Creating identical controlled environment could be the challange for this experiment.