Suppose you conduct a hypothesis test about a population mean when the standard deviation is known (a "z test") by calculating a z statistic and determining whether to reject the null hypothesis. Assume that your z statistic is a positive value and that you will reject the null hypothesis when z is very large. Listed below are possible changes to the study design or to the results of the study. Determine whether the likelihood of rejecting the null hypothesis increases, decreases, or stays the same for each of these changes. Change in Study Design or Results The z statistic
A switch from using a one-tailed test to a two-tailed test ?
A decrease in the population standard deviation ?
An increase in the significance level (such as using a = .05 instead of α = .01) ?
An increase in the sample size (n) ?

Suppose you fail to reject the null hypothesis. Then, the results of your study are .

for b its (t) and c its (d)

step-by-step explanation:

1. sometimes

2.   never

3   .08c = 7.50+.05c   250 pages

step-by-step explanation:

1.   sometimes

the theoretical probability of rolling a 1 is 1/6.   perhaps you got really lucky and never rolled a 1   in those 60 times.   your experimental probability is 0.   or perhaps you rolled a 1   20 times.   your experimental probability is 20/60 is 1/3.     it really just depends on how you rolled in that experiment.

2.   never

the probability of the event occurring is 1.   that is being 100 % sure it will happen.   that is the maximum amount of confidence we have.

3.   no customer card cost:   .08 times number of pages

customer card cost:   7.50 + .05 times number of pages

we want to find when it costs the same amount, so we will set these equal

let c = number of pages

.08c = 7.50+.05c

subtract .05c from each side

.08c-.05c = 7.5+.05c-.05c

.03c=7.5

divide each side by .03

.03c/.03 = 7.5/03

c =250  

the cost is the same at 250 pages