Question

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 5.5 parts/million (ppm). A researcher believes that the current ozone level is not at a normal level. The mean of 31 samples is 5.2 ppm with a standard deviation of 1.0. Assume the population is normally distributed. A level of significance of 0.01 will be used. State the null and alternative hypotheses.

Answer 1

Give

null hypothesis: H0 = 5.5

alternative hypothesis: Ha different 5.5

standard error = 1 / (31) 1/2= 0.1796

we deduce that:

t stat = (5.2-5.5) /0.1796 = -1.67033

p-value = 0.105

the null hypothesis cannot be rejected because the value of p is greater