Stats Help for College-level Students

regression analysis

regression analysis

Statistics: confidence interval and decision making

1. Tourism is one consideration for CoffeeTime's future. A survey of 1,233 visitors to Mumbai last year revealed that 110 visited a small café. Use a 0.05 significance level to test her claim. Would it be wise for her to use that claim in trying to convince management to increase their advertising spending to travel agents? ...continues

Inference for distributions

a). Find the mean IQ scores for girls and for boys. It is common for boys to have somewhat higher scores on standardized tests. It that true? b). Compute 95% T intervals of the Girls' IQ's and the Boys' IQ's and explain what these intervals mean. c). Make a histogram for each set of data to determine whether each distribu ...continues

ANOVA question

There are two groups of sucjects A(n=50) and B(n=60). Each subjects has to test five different concentrations of a solution (5%,10%, 20%, 40%, 80%). When a subject tastes a solution, he gives it a score how he likes it (from 1 to 10). I need to analyze how the ratings depend on group and solution. I am using a two-way ANO ...continues

Chi square test of independence, Confidence interval of variance and standard deviation, Test of hypothesis for difference between means

1) A researcher wishes to determine whether there is a relationship between the gender of an individual and the amount of alcohol consumed. A sample of 68 people is selected and the data are obtained. Alcohol Consumption Low Moderate High Total Gender Male 10 9.13 9 9.93 8 7.94 27 ...continues

Statistics

The data in the table that follows was collected by a large car manufacturer concerning a new prototype car called the CIELO. Thirty carefully selected respondents were shown the car and fully briefed about its capabilities. Here is the data, which includes age (intervally scaled), sex (nominal), social status (interval scale ra ...continues

Probability

1.) If you buy a box of Wisk, the probability of getting a scoop is 97%. If you buy 9 boxes over the next several months, what is the probability of missing two scoops? 2.) The average length of a cellular phone call in the US is 3.4 minutes. If the standard deviation of those calls is .07 minutes (population standard deviati ...continues

Statistics

4.) 20 rivets out 100 in a new box that we tested had break strength below the desired level. Since this is a critical part for assembly, we want to be 99% confident of how many rivets are below the desired level. Calculate the confidence interval of the percentage of rivets that are below the desired level. 5.) We expect a 1 ...continues

Working with combinations.

I have 9 chalkboards to be distributed amongst 4 classrooms. If each class must get at least 1 chalkboard, how many possible divisions can I have?

Normal Distribution

#2 If you are grading the class according to your z score in a normal distribution. would you rather have a score of 70 in class A where the mean is 55 and the standard deviation is 10, or a score of 80 in class B where the mean is 60 and standard deviation is 15? What would the percentile rank be in class A and B and what does ...continues