Josiah Allen

Josiah Allen

University of Alabama at Birmingham

Statistics teacher | Verified Expert

I earned my degree in Statistics from the University of Alabama at Birmingham, where I developed a strong foundation in data analysis and quantitative reasoning. I have a passion for teaching and helping students understand complex statistical concepts. With my academic background and teaching experience, I am equipped to provide clear explanations and effective guidance in Statistics and related subjects. I am committed to helping students succeed and reach their academic goals.


  • The number of accidents is .4 accidents / day. What is the probability that the time from now to the next accident will be more than 3 days?What is the probability that the the time from now to the 3rd accident will be more than 5 days?
  • A recipe has 6 ingredients, how many ways can you arrange the first 4 ingredients?
  • A sample of 50 values has a mean of 8.33 while the population standard deviation is 0.67. According to the Central Limit Theorem, the distribution of sample means is what?
  • What is the central limit theorem?
  • What does "correlation vs causation" mean in statistics?
  • A card is drawn from a standard deck, its color is noted, and then it is replaced in the deck. Another card is then drawn from the deck. What is the probability that the first card is red and the second card is black?
  • If an unbiased die is thrown, what is the probability that it will show a 3 or an even number?
  • How do I find the corresponding x-scores for a z-score of .40, if it has a mean of 7 and a standard deviation of 10?
  • Given a set # {-1,2,-12,52,x} #, for what x would the mean of the set be -3?
  • Suppose your license plate has three digits (between 0 and 9) followed by three letters (between A and Z). If a license number is selected randomly, what is the probability that yours is the one selected?
  • If you roll 5 standard six-sided dice, what’s the probability that you get at least two 4s?
  • What is the probability that the deal of a five-card hand provides exactly one ace?
  • What is the mean and median of 3, 8, 4?
  • Andy has grades of 84, 65 and 76 on three math tests. What grade must he obtain on the next test to have an average of exactly 80 for the four tests?
  • A population 1000 students spends an average of $10.50 on dinner. The standard deviation is $3. A simple random sample of 64 students is taken. What are the expected value and standard deviation of the sampling distribution of the sample mean?
  • A placement exam for entrance into a math class yields a mean of 80 and a standard deviation of 10. How do you find the percentage of scores that lie between 60 and 80?
  • What is the critical value zalpha/2 that corresponds to 88% confidence level?
  • How does significance level relate to confidence level?
  • If the sample size increases, what will happen to the standard deviation?
  • With a fair dice what is the probability of rolling a 1?