A researcher provides 10 children $100 each and another 10 children $20 each. She tracks how they decide to spend the money. Which statement best describes the type of study the researcher is doing?

A. an observational study that is a statistical study
B. an observational study that is not a statistical study
C. an experimental study that is a statistical study
D. an experimental study that is not a statistical study​

Atextile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 kilograms with a standard deviation of 0.5 kilograms. the company wishes to test the hypothesis upper h subscript 0 baseline colon mu equals 12 against upper h subscript 1 baseline colon mu less-than 12 using a random sample of n equals 4 specimens. calculate the p-value if the observed statistic is x overbar equals 11.8. round your final answer to five decimal places (e.g. 98.76543).