Help me on these~

1.Variability in a distribution that would be otherwise non-normal may tend towards normality with random sampling. true or false ?

2. Which of the following is not included as one of the founding principles that makes up the guidelines for an Institutional Review Board (IRB)?

-Beneficence

-Justice

-Informed consent

-None of these are correct

3. Which of the following is an incorrect pairing of a statistic and its interpretation?

-The mean of a distribution describes the gravitational center of all of the observations.

-The standard deviation is an average of the sum of squares in a distribution.

-The mode of a distribution indicates the observation with the most weight in a distribution.

-Fifty percent of the observations in a distribution fall above and below the median value.

4.A confidence interval that includes the null hypothesis may still result in a statistically significant association. True? False?

5. Which of the following statements regarding confidence intervals isleastaccurate?

-As you increase the confidence level , the precision of your estimate decreases

-As you decrease the confidence level , the precision of your estimate increases

-Establishing a higher level controls for nonrandom sources of error due to bias

-Confidence intervals are established to account for random error in sampling

6. Which of the following describes an experimental, placebo controlled study?

-Epidemiologists are interested in the association between mold in homes and wheeze in young adults so they conduct an investigation looking at the exposure and outcome relationship

-A clinical trial is organized to test the efficacy of a new drug intended to treat high cholesterol, where participants aren't sure if they are receiving the experimental drug or not.

-A clinical trial is organized to test a new chemotherapy on its ability to increase progression free survival (PGA) and is randomly offered to half of the participants, while the other half receive best standard care.

-Researchers are interested in the causal relationship between periodontal disease and hypertension so they observe the results from 10 different studies looking at the relationship and compile the results into one report in a meta-analysis