What is the price of a 12 dollar game 30% off

Can someone me and do the problem plz so i can understand it more better

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1

Astudy claims that the mean age of online dating service users is 40 years. some researchers think this is not accurate and want to show that the mean age is not 40 years. identify the null hypothesis, h0, and the alternative hypothesis, ha, in terms of the parameter μ. select the correct answer below: h0: μ≥40; ha: μ< 40 h0: μ≤40; ha: μ> 40 h0: μ≠40; ha: μ=40 h0: μ=40; ha: μ≠40