can you please give me the formulas to find the answers . that's an exercise of business statistics

Joselyn hopes to receive a grade of B or better in her statistics class. Currently she has scored 75, 83, and 81 on her three in-class tests and also has a homework average of 88. Her professor calculates the class grade by finding the mean of five grades: three in-class tests, the homework average and the final exam. What is the minimum score Joselyn must earn on the final exam to have a class grade (mean) of 80? A. 67 B. 95 C. 70 D. 73

Last semester, Bonnie took a different Biology teacher than her friend Tony. After the final exam, they compared test scores. Bonnie earned an 83 (mean = 75.6, sd = 5), and Tony earned an 87 (mean = 80.3, sd = 7). Who did better? Why?

using the picture included to answer Besides a bar chart, what would be another appropriate graph to display this data set?

Martha is in a statistics course in which each exam has a total of 100 points possible.  Martha currently has an average score of 88 on her statistics exams.  If she earns a score of 95 on her final exam, Martha's average

Discuss how statistics, as a way of organizing and summarizing data, helped make good decisions when shopping

The study of statistics can be intimidating, but it can also be rewarding. Describe at least two benefits to your life as a student by engaging in the study of statistics

A student has an average of 81 on four equally weighted tests she has taken in her statistics class. What grade must she receive on her fifth test if she needs an average score of 83? Answer is 91? Can you help me to explain to me step by step?

Please explain

You land a job at an online marketing/consulting firm after attaining a business degree with an emphasis in statistics. You walk into your office on the first day and there is an assignment sitting upon your desk. The firm was recently hired by ImpulseBuy Now.com (a famous online clearing house for as-seen-on-TV junk items). ImpulseBuyNow wanted to know if the amount of time spent browsing by a customer at their online site associates to how many items the customer purchased. Sound familiar? Realizing that you listed a statistical emphasis in your business degree, you panic and pull out your old statistics notes as to find this unit in the study guide. What luck! You must figure out what to tell ImpulseBuy Now about their question. Here is the data provided by ImpulseBuy Now: Browse Time (min.) 0-10 11-20 More than 20 Browse Time (min.) 0-10 Items Purchased Zero 1000 And your final p-value is extremely small. 1500 500 One 900 Expected Values Zero 600 2600 2500 Your paycheck depends…