The flu shot changes every year in an effort to predict the strain that will be going around each year, and some years it is more effective at preventing the flu than others. A group of researchers wants to compare the effectiveness of the flu shot this year to the flu shot last year.

Null:

Alternative:

Is this hypothesis directional or non-directional?

Type I Error:

Type II Error:

Null:  This year flu shots effectiveness is no good than that of used last year and before...

Alternative: This year flu shots effectiveness is better as compared to those of used last year and before...

This hypothesis is directional due to the congruence wit all the facts in a chronological order and so...

Type I Error:  Rejection of true null hypothesis

Type II Error: Non-Rejection of of a false null hypothesis

if a group of researchers want to compare the effectiveness of the flu shot this year to the flu shot last year then is a directional hypothesis

Explanation:

A directional hypothesis this is simply the prediction made by a researcher concerning a positive or a negative change, relationship, or difference between the two variables that are being contained in a population.

A type I error: this is simply a situation whereby we a reject a true null hypothesis. while

A type II error is simply the non-rejection of a false null hypothesis.

what effect does exercise have on the nervous system?

the answer is c.