Catalina read a report saying that the average daily high temperature in Buenos Aires a few years ago was 18.2°C. She believes that last year was warmer than this. To test her belief, she takes a simple random sample of 20 days from last year and records the daily high temperature on each chosen day. Let μ represent the average daily high temperature in Buenos Aires last year. Which of the following is an appropriate set of hypotheses for Catalina's significance test?
a). H₀:μ = 18.2°C
Hₐ:μ > 18.2°C
b). H₀:μ > 18.2°C
Hₐ:μ = 18.2°C
c). H₀:μ > 18.2°C
Hₐ:μ does nor equal 18.2°C
d). H₀:μ= 18.2°C
Hₐ:μ < 18.2°C