Linked Questions

2
votes
3answers
225 views

Large sample confidence interval

Can someone please be so kind to check if my answer is correct
2
votes
1answer
494 views

Conduct a Wald test and construct a 95% Wald confidence. Are these sensible?

Question: In a crossover trial comparing a new drug to a standard, $\pi$ denotes the probability that the new one is judged better. it is desired to estimate $\pi$ and test $H_0:\pi=0.50$ against $H_a:...
1
vote
1answer
435 views

Weaknesses of Wald confidence interval for binomial distribution

A survey samples $1000$ people, among which $500$ say they will vote for $A$, $400$ for $B$ e $100$ for $C$. Calculate a confidence interval for the proportion of people that will vote for $A$. What ...
4
votes
3answers
93 views

Is it okay to divide something by a random variable that can take on the value of 0 with probability greater than 0?

Is it okay to divide something by a random variable that can take on the value of 0 with probability greater than 0? For example, we know that, by using Slutsky's Theorem, If $\hat{p^*} = \frac{Y}{n},...
0
votes
1answer
254 views

Binomial confidence intervals and the Central Limit Theorem

Suppose I want to estimate the head probability p for a biased coin. Usually this is done by assuming the distribution tends to normal using large number of trials and CLT. I am wondering how robust ...
2
votes
2answers
208 views

Confidence interval in statistics

I really need help on this question. I am taking an introductory statistics class, and here is the question: A taxi company wants to determine if customers will accept self driving cars. The company ...
1
vote
1answer
95 views

Confidence interval for population proportion

You have a population of 10M people. Suppose you want to determine the share of people with a certain disease. To do so you randomly choose X people and check if ...
0
votes
0answers
104 views

90% Confidence Interval for Population Proportion Given p' and n

I am trying to figure out why, for finding confidence intervals, we use the following standard error $$SE = \sqrt{\frac{p(1-p)}{n}}$$ in the formula $$ \overline{X} \pm z_{(\alpha / 2)} \times SE$$ ...
2
votes
1answer
48 views

Find the 99% confidence interval (Interval and test for proportion)

I have the following question and I am getting different results from a friend (I think he forgot to halve $ \alpha $). Problem is: A random sample of 100 students from a large school was taken. It ...
0
votes
1answer
69 views

Confidence Interval and Central Limit Theorem

Here's the problem: "During a test, we asked $120$ people who Jean-Jaques Rousseau was, and $12$ of them answered that he was a driver (which is false). Estimate the proportion of the population ...
1
vote
1answer
62 views

Computing confidence interval of a proportion using prop.test() in R

I am using prop.test() to calculate the confidence interval of a proportion. I found that prop.test() result differs from the z-...
1
vote
1answer
31 views

Statistics - Calculate probability of occurrence from small number of tests

I'm sure this is basic statistics, but I'm not even sure of the right words for the concepts I'm dealing with. I took statistics in college but it was ... well ... a few years ago. Let's say there's ...
0
votes
1answer
40 views

How to pick sample size?

I have a requirement where i want to perform testing of 1000 systems, but I want to limit or pick or sample size since the rest is assumed to have same configuration. Whats criteria to pick sample ...
1
vote
1answer
27 views

What sampling distribution does $\hat{p}$ in this scenario follow?

Homework question, not sure whether I should be using a normal distribution, a binomial distribution or a hypergeometric distribution. A mail-order company promises its customers that the products ...
-1
votes
1answer
32 views

Calculating statistical significance

I have a dataset that holds the number of times a group of people used a type word in a survey at three different data collection points: People in Group - 158 People who use a word at T0 = 123 ...