Approximately how old is the moon thought to be?
a. 1 billion years
b. 2.1 million years
c. 3.8 billion years
d. 4.5 billion years

Describe how you could move the flashlight above the paper to

The federal reserve is responsible for overseeing all a. income tax refunds b. changes in tax policies c. government spending d. depository institutions

What is the difference between an observational study and an​ experiment? choose the correct answer below. a. in an​ experiment, a treatment is applied to part of a population and responses are observed. in an observational​ study, a researcher measures characteristics of interest of a part of a population but does not change existing conditions. b. in an​ experiment, a treatment is applied to an entire population and responses are observed. in an observational​ study, a researcher measures characteristics of interest of an entire population but does not change existing conditions. c. in an​ experiment, a researcher measures characteristics of interest of a part of a population but does not change existing conditions. in an observational​ study, a treatment is applied to part of a population and responses are observed. d. in an​ experiment, a researcher measures characteristics of interest of an entire population but does not change existing conditions. in an observational​ study, a treatment is applied to an entire population and responses are observed.