Question

8. A random sample of 20 watermelon seeds is harvested from each of 4 different varieties of watermelons. Within each variety, 10 seeds are randomly chosen to be soaked in water for 24 hours before being planted in individual seed starting trays. The remaining 10 seeds from each variety are simply planted individually in seed starting trays. After one week the heights of the seedlings are measured. What type of study design is this? an experiment based on a matched pairs design an observational study based on a simple random sample Oan experiment based on a randomized block design an observational study based on a stratified random sample an experiment based on a completely randomized design

Answer 1

Ans. The Total population size = 10*4 = 40 seeds

Variety of watermelon = 4

Each variety has 10 seeds

The sample size n = 20

Here we have 4 srtar ( variety of seeds) and each strata has 10 observations (seeds)

We select a simple random saple from each strutum I dependently in such way that the combined sample has 10 seeds, such type of sample is known as stratified random sample and the procedure of drawings the sapmle is known as stratified random sampling.

thus the correct answer is an observationtional study based on a stratified random sampling.