What is the null hypothesis for a two-tailed test against a known population mean of 90?

Restrictions on f(x) = 1/x+5 and g(x) = x-2

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?

Which statement describes surface features called maria on the moon