Question

Clinical literature reports that the duration of a typical cold is roughly 18 days. Researchers wanted to know if people tend to underestimate the duration of a typical cold, on average. They surveyed a random sample of 352 healthy adults in Georgia and asked them how long they think that a typical cold lasts. The researchers reported a 95% confidence interval of 6.9 to 8.2 days for the mean expected duration of typical cold. What are the null and alternative hypotheses that these researchers wanted to test?

H0 : μ = 18 vs. Ha : μ < 18 H0 : μ = 18 vs. Ha : μ ≠ 18 H0 :  = 7.55 vs. Ha :  ≠ 7.55 H0 : μ = 6.9 vs. Ha : μ < 8.2

Answer 1

Here, we need to find null and alternative hypotheses that these researchers wanted to test

H0 : μ = 18 vs. Ha : μ < 18