The null and alternative hypotheses are given. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed and the parameter that is being tested. H0: σ = 8.6 H1: σ < 8.6

Test is Left tailed test

Parameter tested is standard deviation

Step-by-step explanation:

We are given the hypothesis as;

Null hypothesis; H0: σ = 8.6

Alternative hypothesis; H1: σ < 8.6

Where;σ is a constant generally known in statistics as the standard deviation.

Now, it's the alternative hypothesis that will let us know whether this is left tailed, right tailed or two tailed.

Alternative hypothesis says σ < 8.6.

This means that the values of σ that satisfy this hypothesis are less than 8.6 and thus are on the left hand side of 8.6 on a number line. Thus, the shaded region in a normal distribution curve will be on the left.

Thus, it's a left tailed test

step-by-step explanation:

(s)he  is right it would be 5.5% because it is smaller than 15.5% or anything smaller than 15.5% in general