Question

2. What is the term for the entire group in which a researcher is interested? 3. “A statistic is calculated based on a sample.” True or false? 4. “A parameter is an estimate of a statistic”. True or false? 5. Identify the independent and dependent variables in each example. a) You want to see which type of fertilizer helps plants grow fastest, so you add a different brand of fertilizer to each plant and measure how tall they grow. b) You are interested in how rising sea temperatures impact algae, so you collect and measure the number of algae in samples of water taken from ocean sites under varying temperatures

Answer 1

Problem statement: Few statements regarding statistical concepts are mentioned. We have to answer questions based on those statements.

Problem (2) : Term used for group of people researcher is interested in is called "treatment group".

Explanation: In every experiment, researcher would like to study the effect of intervention (treatment), so he/she divides the samples in to groups receiving treatment and other group as baseline (control group). So "treatment group" is what the researcher is interested in.

Problem (3): Yes a statistic is calculated from a sample. Statistic can be considered as measurements computed from a data sample.

Problem (4): Parameter is defined as an unknown constant in the population. We use statistic to estimate the parameter in the population. So the answer is false, strictly speaking since parameter is defined in the population. But yes, a "parameter estimate" is an estimate based on the statistic computed from data. We can estimate the parameter but its true value remains unknown.

Problem (5): By definition, independent variable has a relation with the dependant variable, based on which a change in independent variable value has an effect on the dependent variable outcome.

Problem 5 (a): Different brands of fertilisers are independent variable while growth of plant is dependent variable, since it is assumed that change in fertiliser quantity / brand has an effect on plant growth.

Problem 5 (b) : It is assumed that number of algae is affected by rising sea temperatures. So, number of algae is the dependent variable and oceanic temperatures form the independent variable.