Please help me I don’t understand

Which statement describes the term economics? a. it is the study of using limited resources to fulfill wants and needs. b. it is the study of how governments fulfill the wants and needs of nations. c. it is the study of how people spend their money to fulfill wants and needs.

The contents of 3838 cans of coke have a mean of x¯¯¯=12.15x¯=12.15. assume the contents of cans of coke have a normal distribution with standard deviation of σ=0.12.σ=0.12. find the value of the test statistic zz for the claim that the population mean is μ=12.μ=12.

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?