Question

7.A public speaker gives anywhere from 0 to 5 speeches each week. Here is a probability distribution table for X, the number of speeches given during any given week: X P(X) 0 0.14 1 0.16 2 0.19 3 0.23 4 0.14 5 0.14

For this probability distribution, ??≈2.5, and ??≈1.6. What is the probability that in any given week the speaker will give a number of speeches that is within one standard deviation of the mean?

8. If the weights of a certain type of candy bar are normally distributed, with mean 2.50 ounces and standard deviation 0.04 ounces, to the nearest ten-thousandth what proportion of candy bars weigh between 2.46 ounces and 2.59 ounces?

9. If the weights of a certain type of candy bar are normally distributed, with mean 2.50 ounces and standard deviation 0.04 ounces, to the nearest hundredth what is the weight of a candy bar which is heavier than 25% of the bars?

10. Find a 90% confidence interval for the weights of squirrels if a sample of 17 squirrels had a mean weight of 497.2 grams, with a standard deviation of 26.3 grams. Round to the nearest tenth.

Answer 1