Statistics !!

[Mina.m]

does anyone know how to do ANY of the following questions !! i just cant get it !!!


Question 2.   (Statistical Inferences: Single Population)

Feasibility Study: Companies that sell groceries over the Internet are called e-grocers. Customers enter their orders, pay by credit card and receive delivery by truck. To determine whether an e-grocery would be profitable in one large city, a potential e-grocer offered the service and recorded the size of the order for a random sample of customers. The data are stored in the data file.

(i)   Estimate with 95% confidence the average order in the city.
(ii)   Financial analysis indicates that to be profitable the average order would have to exceed $85. Can we infer from the data that an e-grocery will be profitable in the city? Test using  = 0.05.





Question 3.    (Statistical Inferences: Two Populations)

To sell or not to sell: The fluctuations in the stock market induce some investors to sell and move their money into more stable investments. To determine the degree to which recent fluctuation affected ownership, a random sample of 170 people who confirmed that they owned some shares were surveyed. The values of the holdings were recorded at the end of last year and at the end of the year before. Can we infer that the average value of the shareholdings has decreased? Use  = 0.05.



 
Question 4.   (Simple Linear Regression)
 
Insurance Premium: A health economist is investigating whether there is any relationship between people’s age and their medical expenses. He gathered data concerning the age and average daily medical expenses of a random sample of 320 Australians during the previous 12-month period. The data are stored in the data file.

(i)   Determine the equation of the regression line to predict the daily medical expense by a person’s age.
(ii)   Interpret the coefficients.
(iii)   Find the coefficient of determination. What does this statistic tell you abut the regression line?
(iv)   Can we conclude at a 5% significance level that higher ages result in higher daily medical expenses?
(v)   Predict with 95% confidence the daily medical expense of a 60-year-old Australian.

[Mina.m]

finally managed to get it done.. how do u delete this thread??  thanx anyways

[Gloamglozer]

Up near "Quote" and "Modify" next to the date of your first post, there should be a button called "Remove".  Click that.

[Hooligan]

question: was there meant to be any data attached with these questions? 'cause it seems almost impossible to me, to do, without any data... like 2i)... or maybe there is data... but I can't see it?  :laugh:

[plato]

Most of the questions you had asked about do not belong to the Further Maths study design. You can ignore Confidence and significance levels.