Statistics and Probability Answers

Medical literature tells us that our blood is mainly composed of red and white blood cells corpuscles and a normal human body must average 7250/mm³ of white blood cells counts. If a sample of 15 individuals chosen at a random from a certain place has an average of 4850/mm³ with a standard deviation of 2500/mm³ would you say that the people in that place have low white blood cell counts

In a Science test, the mean score is 42 and the standard deviation is 5. Assuming the scores are normally distributed, what percent of the score is:

14. Between 30 and 48?

If the systolic blood pressure for a certain group of obese people has a mean of 132 and a standard deviation of 8, find the probability that a randomly selected person will have below 148 blood pressure. Assume the variable is normally distributed.

1. The number of accidents in a production facility has a Poisson distribution with a mean of 2.7 per month. For a given month, what is the probability that there will be more than three (3) accidents?

Four coins are tossed at once. Let Y be the random variable representing the number of

heads that occur.

Assumed that the fill amount in 2-liter soft drink bottles is normally distributed, with a mean of 2.0 liters and a standard deviation of 0.05 liter. If bottles contain less than 95% of the listed net content (1.90 liters, in this case), the manufacturer may be subject to a penalty by the state office of consumer affairs. Bottles that have a net content above 2.10 liters may cause excess spillage upon opening. What proportion of the bottles will contain (a) between 1.90 and 2.00 liters? (b) between 1.90 and 2.10 liters? (c) below 1.90 liters or above 2.10 liters? (d) At least how much soft drink is contained in 99% of the bottles? (e) 99% of the bottles contain an amount that is between which two values(symmetrically distributed) around the mean?

The amount of time spent by North American adults watching television per day is normally distributed with a mean of 6 hours and a standard deviation of 1.5 hours. (a) What proportion of the population watches television for more than 7 hours per day? (b) What is the probability that the average number of hours spent watching television by a random sample of five adults is more than 7 hours? (c) What is the probability that in a random sample of five adults all watch television for more than 7 hours per day?

The amount of time spent by North American adults watching television per day is normally distributed with a mean of 6 hours and a standard deviation of 1.5 hours. (30%) (a) What proportion of the population watches television for more than 7 hours per day? (b) What is the probability that the average number of hours spent watching television by a random sample of five adults is more than 7 hours? (c) What is the probability that in a random sample of five adults all watch television for more than 7 hours per day? 

A subdivision household collects an 20 killos of trash each week. If the standard deviation is 3.5 kilos based on the assumption that the data collected are normally distributed, find the probability that a household selected at random collect trash of:

a. lower than 16 kilos

b. greater than 22.5 kilos

c. between 14 kilos and 23.5 kilos

d. 11 kilos and 15 kilos