Question

1. what is the range of the function graphed below?

a) all real numbers greater than or equal to 0
b) real numbers greater than or equal to 0 and less than 2
c) all real numbers greater than or equal to 2
d) all real numbers less than or equal to 2

1. a scientist aimed to investigate the effects of meditation on anxiety levels in university students. she implemented the following data collection method:

the scientist randomly chose 60 students for the study. thirty students were instructed to practice 20 minutes of meditation daily for two weeks, while the remaining 30 students were told to refrain from any meditation during that period. at the end of the two weeks, the scientist assessed the anxiety levels of all participants using a standardized anxiety scale.
is this an experiment or a sample survey?
a) experiment
b) sample survey

1. a researcher wanted to study the impact of exercise on stress levels among college students. she designed the following method of data collection:

the researcher randomly selected 50 students to participate in the study. twenty - five students were instructed to engage in 30 minutes of aerobic exercise daily for one week, while the other 25 students were asked to avoid any form of exercise during that week. at the end of the week, the researcher measured the stress levels of all participants using a standardized stress scale.

• is this an experiment or a sample survey?

a) sample survey
b) experiment

1. a researcher is interested in understanding the impact of social media usage on sleep quality among college students. she uses the following approach to gather data:

method: the researcher interviews 150 randomly chosen college students, asking them about their daily social media usage in hours and their average sleep duration per night. she then examines the data to identify any correlations between social media usage and sleep quality.
is this an observational study or a controlled experiment?
a) simple survey
b) controlled experiment

Explanation:

Step1: Analyze the graph's y-values

The graphed function (likely exponential/logarithmic) has its lowest point at y=2, with no upper bound.

Step2: Match to range options

Range is all real numbers ≥2, which corresponds to option c.

Step3: Identify experiment vs survey (Q23)

The scientist manipulates the independent variable (meditation) → experiment (option a).

Step4: Identify experiment vs survey (Q24)

The researcher manipulates exercise (independent variable) → experiment (option b).

Step5: Identify observational vs controlled (Q25)

No manipulation—only interviews and correlation analysis → observational (option a, assuming typo: "simple survey" aligns with observational).

Answer:

1. c) all real numbers greater than or equal to 2
2. a) Experiment
3. b) Experiment
4. a) simple survey