A Schoolteacher Is Worried That the Concentration of Dangerous, Cancer-Causing

Multiple Choice

A schoolteacher is worried that the concentration of dangerous, cancer-causing radon gas in her classroom is greater than the safe level of 4pCi/L. The school samples the air for 36 days and finds an average concentration of 4.4pCi/L with a standard deviation of 1pCi/L. To test whether the average level of radon gas is greater than the safe level, the appropriate hypotheses are ________.

A) H₀: μ ≤ 4.0, H_A: μ > 4.0
B) H₀: μ = 4.0, H_A: μ ≠ 4.0
C) H₀: μ ≥ 4.4, H_A: μ < 4.4
D) H₀: = 4.4, H_A: X ≠ 4.4