Statistics and Probability Answers

An auto battery company claims that their batteries' mean life is 50 months. In order to check this cla, a DTI researcher took a random sample 18 of these batteries and found that the mean life is 48.8 months with standard deviation of 7 months. Aasume the battery life follows a normal destribution, test with 90% confidence wether the companies'claim is different from the true mean.

1. The mean lifetime of a sample of 100 light bulbs produced by a certain company is found to be 1580 hours. Test the hypothesis at 5% level of significance that the mean lifetime of the light bulbs produced by the company is 1,600 hours with sd of 90 hours.

I have 6 colors which is Blue, Red, Yellow, Orange, And Green and each of them is equal to each other, so now what is the propability that i will get red?

2. The mathematics teacher claims that the mean IQ of Statistics students is 110 with standard deviation of 12. The mean IQ of 28 randomly selected Statistics students is 112. Test the difference of the population and sample means at 5% level of significance.

What is the t value of the distribution with a= 1% and n=8 under the one tailed distribution

A positive z-score always corresponds to an X value greater than the mean. True or False?

Comparing the survey results of votes to the actual votes received by a candidate 

in an election. Identify if it is two tailed or one tailed

A certain area of the eastern United States is, on average, hit by 6 hurricanes a year. Find the prob-ability that in a given year that area will be hit by (a) fewer than 4 hurricanes; (b) anywhere from 6 to 8 hurricanes.