(1) The average number of humming birds per hour on a particular feeder is 5. Find the probability that exactly 3 humming birds feed during a particular hour using the correct table or formula.

(2) Weights for students applying to a Sumo wrestling school are normally distributed, with a mean of 250 pounds and a standard deviation of 25 pounds. To be eligible to enter, a person must weight in the top 15%. What is the lowest weight a student can have and still be eligible to enter the school.

(3) Determine the minimum required sample size if you want to be 95% confident that the sample mean is within 2 units of the true population mean. Assume that sigma = 7.8 is known and that the population is normally distributed.

(4) A horticulturalist wants to study the growth rate of a particular variety of Bougainvillea. From a sample of 16 randomly selected Bougainvilleas, the mean growth rate was 2.23 inches/week and the sample standard deviation was 0.77 inches/week. Find a 90% confidence interval for the mean growth rate of all Bougainvilleas.

Solution Summary

The solution gives step by step method for calculation of probability from normal distribution using z score.

... for the IRS site computed in Problem 6.52 to ...Normal Probabilities (a) Normal Probabilities (b). ... Mean Standard Deviation 0.5 Standard Deviation Probability for ...

... Statistic problems 1. Find the following probabilities: ... cumulative X p(X) probability 0 0.88638 0.88638 1 0.10744 ... 6. X has a normal distribution with a mean of ...

... If we want to find the probability of an error of 0.75 V ... 2) [ X − 100] / σ ~ N (0,1) (3) You can look up a table for the standard normal distribution N(0,1 ...

... solution addresses 10 short-answer basic statistic questions. ... that X follows a normal distribution N ... its characteristics is the probability density function. ...

... d) The probability that a ... the calculation of probabilities, conditional probabilities and normal probabilities. ...Problem Set 2 Acme Tires manufactures two types ...

... 3- In the above problems involving samples, we have used the normal distribution probability table to calculate probabilities involving the means of the samples ...