Is a survey that asks the opinions of students about a proposed tour program to a hill station an observational study or experimental study? if it is an experimental study, what is the controlled factor? (a) the study is an experiment. the controlled factor is the students. (b) the study is an observational study. (c) the study is an experiment. the controlled factor is the hill station. (d) the study is an experiment. the controlled factor is the survey

(B) The study is an observational study.

Step-by-step explanation:

A study in which a researcher observe the behavior of the participants in a certain manner without interfering then is known as observational study. There is no control over the variables.

On the other hand , In experimental study has control over one or more controlled factors to study the change in dependent factor .

A survey that asks the opinions of students about a proposed tour program to a hill station is an observational study because there is no controlled factor .

Every body has their own opinion with any dependence.

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)