Statistics and Probability Answers

2. Your friend is asking you to invest in his bakery, and you have 35000. The returns are  volatile, and you may get either 43000 with a probability of 0.44 or 27000 with a  probability of 0.56. 

a. What is the expected value of the investment?  

b. Will you buy the refrigerator? Why? 

c. Identify the mean, variance, and standard deviation.

Your friend is asking you to invest in his bakery, and you have 35000. The returns are volatile, and you may get either 43000 with a probability of 0.44 or 27000 with a probability of 0.56.

The width of white board markers manufactured by a company is approximately normally distributed with a mean of 12 mm (millimetres) and a standard deviation of 4 mm. If a random sample of size 16 white board markers is selected, what is a) the distribution of the mean? b) the probability that the sample mean is less than 15.6 mm? c) the probability that the sample mean is between 12.8 mm and 13.2 mm?

5. The number of oranges that grow on an orange tree in Florida is normally distributed with a mean of 136 with a standard deviation of 21 oranges.

a. What percent of the trees grow less than 150 oranges?

b. What percent of trees grow between 90 and 110 oranges?

c. How many oranges does a tree grow if it is in the top 20% of orange producers?

A newspaper article estimated that the mean cost for preventive dental care was $165 per year. They indicated that the estimate was based on a sample of 100 people and that the margin of error was 2.8. Assuming a 95% confidence level was used, calculate the value of the standard error.

For the following data, find the correlation co-efficient. How much 𝒙 depends on 𝒚?

Determine and sketch the corresponding regression line. Graphically find the value of 𝒙

when 𝒚 = 𝟏𝟓.

• 𝒙: 5 12 18 23 27 30 26 22
• 𝒚: 18 16 13 11 9 7 10 13