Select all ratios equivalent to 9:7

Me because some of question i don’t understand

Solve the equation below: (x+4)/6x=1/x a. x=2 b. x=0,2 c. x=-2 d. x=0,-2

(b) suppose that consolidated power decides to use a level of significance of α = .05, and suppose a random sample of 100 temperature readings is obtained. if the sample mean of the 100 temperature readings is x⎯⎯ = 60.990, test h0 versus ha and determine whether the power plant should be shut down and the cooling system repaired. perform the hypothesis test by using a critical value and a p-value. assume σ = 5. (round your z to 2 decimal places and p-value to 4 decimal places.)