Use the One-Proportion Z-Test to Perform the Required Hypothesis Test

Use the one-proportion z-test to perform the required hypothesis test. Use the critical-value approach.
-A research group claims that fewer than 28% of students at one medical school plan to go into general practice. It is found that among a random sample of 120 of the school's students, 20% of them plan to go into general practice. At the 0.10 significance level, test the research group's claim.