Which statistical treatment to use.

My niece is asking me help in doing her science investigative project. Well we are stuck in which statistical treatment to use. Here is the gist of her project.

It’s like this. They plant a fortune plant in a soil with acid phosphate and egg shells and another one in a soil with acid phosphate and mussel shells. They observed for 7 days and recorded the height of the two plants. They want to compare the two.

I just need some advice which statistical treatment should be used. Should I use ANOVA or t-test? I haven’t done these kind of things since high school but I think l can study it by myself if I’m pointed in the right direction. Thanks guys.

Given that there are only two plants, isn’t statistical treatment irrelevant?

Just two numbers – the height of each plant after seven days? You can’t do statistical analysis on two numbers.

Now, if you measured the height of each plant every seven days over the course of (for example) 60 days, you can do something with the data.

They did record the height of the plants every day for 7 days. I told her to just describe the results they gathered since there’s no point using a statistical test. Thanks guys.

You could plot both data on the same graph: time on the independent (x) axis, height on the dependent (y) axis.

Is the growth fairly linear over time? If so, you could do a 1st-order curve fit on each (a.k.a. linear regression, least squares fit), and compare slopes.

I want to know where to get a fortune plant.

Following up on this idea, the statistical test to compare coefficients of two regression lines is called the Chow test (ironic, given the OP’s username).