Topic: Statistics using excel
Order Description:
This course work is regarding distribution of sample mean and estimation of population mean.
If for any questions you need to refer to normal distribution chart, I have attached them separately.
Please use excels (use formula such as NORM. INV if applies) to solve Question 1 and Question 2. Please attach your answers in the word document as well as upload the original excel work sheet or workbook so that I can edit them if I need to.
Question 1:
We know from previous data that that weight of oranges for export x:N (300, 252) (unit in grams) follow the normal distribution. It is important that all oranges for export have to be in similar size so we need to exclude oranges too big or too small for export. We have decided to use 90% for confidence coefficient for the evaluation standards for oranges too big or too small. Please find the upper and lower confidence limit.
Hint: the answer is to exclude oranges below 258.9g and above 341.1g when calculated by hand.
Question 2:
In relation to Question 1 above, is orange weighing 250g considered significantly small with 95% confidence coefficient
Hint: the answer is around 251g when calculated by hand. Therefore when comparing 251g to 250g , 250g is smaller and therefore is significantly small.
Please use excels (use formula such as NORM. INV if applies) to solve Question 3. Please attach your answers in the word document as well as upload the original excel work sheet or workbook so that I can edit them if I need to.
Hint: when you want to make the statistical error smaller, you change the sample size (to bigger) so that the standard deviation will change
Question 3 Part 1:
We know that the weight of certain product is σ = 20 (g) and follows the standard deviation. We want to estimate the mean of the weight of the product. Using confidence coefficient 95% , solve how big the sample size should be if we want to make the range of confidence interval (that is twice the statistical error) below 5 (g).
Hint: the answer is around 246 when calculated by hand.
Question 3 Part 2:
Please solve how big the sample size should be if we were to make overall product’s average weight be confidence coefficient 90% and range of confidence interval 10(g).
Hint: the answer is around 44 when calculated by hand.
Please use excels (use formula such as NORM. INV if applies) to solve Question 4. Please attach your answers in the word document as well as upload the original excel work sheet or workbook so that I can edit them if I need to.
Question 4 Part 1:
From the previous experience, we know that standard deviation of average of 6th grade student is 6cm.
When estimating the population mean of 36 6th grade students, solve the range of confidence interval when confidence coefficient is 95%.
Hint: the answer: one side of the range of the confidence interval is 1.96cm and both sides are 3.92cm when calculated by hand.
Question 4 Part 2:
We are estimating the population mean with sample average of height of 81 6th grade students. What is the confidence coefficient when the range of confidence interval is 3.4cm?
Hint: the answer is 98.92% when calculated by hand.
Please make sure that all answers are pasted on to word document as well as attach your excel file (your excel sheet or excel workbook) so I can edit or refer to it. Please set up your excel worksheet so that I can print out the work on excel nicely on A4 paper. The printed out work of excel should be no more than 3 A4 papers. Make sure you label your work (which questions you are working on) on excel.