# Statistical significance

A researcher collected ten questions in a survey about minority rights. 3000 randomly selected people living in California participated in the survey. She created a score of support for minority rights. Negative values mean opposition to minority rights; positive values indicate that the opinions are in favor of it. The researcher wants to know if the population’s average opinion in California supports minority rights. Due to privacy reasons, the researcher only had access to some sample summary statistics, such as the average, standard deviation, etc.

(a) Suppose that the researcher is informed that the sample avarage is xbar =4 and the sample variance is ˆσ2 = 4. Can she infer, with statistical significance, that the average opinion in the population in California is not neutral? Select a significance level and answer this question based on your selection.

(b) Suppose now that two mistakes occured. The company collecting the data changed places where some zeros should go when they sent the report to the researcher.

They called the researcher and said the sample size was actually 30, not 3000, and the vari- ance 400, not 4. Using a normal approximation for the sampling distribution of the mean, given this new information about the variance and the sample size, and using the same signif- icance level you selected in the previous item, can she conclude that the opinion is statistically significant not neutral? Using your own words, explains why the result changed or did not change.

## Answer

**Answers can only be viewed under the following conditions:**

- The questioner was satisfied with and accepted the answer, or
- The answer was evaluated as being 100% correct by the judge.

- answered
- 467 views
- $17.50

### Related Questions

- Compute the cumulative density function of X
- A miner trapped in a mine
- Can someone explain why the attached R-Studio Code, provided by the author, does not create the output like in his book?
- A gamma function problem
- One Way Anova
- How would I perform an exploratory data analysis to visually assess the relationship between two sets of data?
- Probabilities
- Assess team win rate by combining individual win rates?

If you wonder what a reasonable bounty is, think about how much a private tutor would charge to help you with your problems.

I am guessing you are suggesting I increase the price. I have never been to a private tutor so I really don't know how much a reasonable price is. I am guessing, based on the complexity/ease of my questions, that this would be a fair price.

While it's true that your question is not especially difficult, it's still time-consuming to write a proper answer, that's why Philip is telling you to increase your bounty. Private tutor prices tend to vary, for what I have seen they can go from 20$/h to 100$/h or more, depending on the qualifications, low tier being e.g. an undergrad, top tier a PhD with experience in teaching and tutoring. Also, keep in mind that the website takes a 20% cut, so adjust accordingly.

Thanks for the info. First time using this site so I'm quite the noob at the moment.