Find confidence interval for difference between two years

Reference no: EM13123282

A market research firm supplies manufactures with estimates of the retail sales of their products from samles of retail stores. Marketing managers are prone to look at the estimates and ignore sampling error. An SRS of 75 stores this month shows mean sales of 52 units of a small appliance, with standard deviation 13 units. During the same month last year, an SRS of 53 stores gave mean sales of 49 units, with standard deviation of 11 units. An increase from 49 to 52 is a rise of 6%. The marketing manager is happy because sales went up 6%.

Q: Should the manager be happy about this improvement? Explain using a significance test.

B. Find a 95% confidence interval for the difference between this year and last year in the mean number of units sold at all retail stores and interpret the results.

Reference no: EM13123282

Questions Cloud

High-low method of cost estimation : Ingram Co. manufactures office furniture. During the most productive month of the year, 3,500 desks were manufactured at a total cost of $84,400. In its slowest month, the company made 1,100 desks at a cost of $46,000.

Vertex chromatic numbers and betti numbers : In the page 82 B(G) is defined like independent sets like you say but in the page 187 it other kind of B and it is define like Betti number and it is defined below

How much cl2 can be produced : NaCl(aq) + H2O(l) → NaOH(aq) + Cl2(g) + H2(g). If the brine contains 389 g of NaCl, how much Cl2 can be produced.

Merely supported beam- maximum bending moment : Simply supported beam- Maximum bending moment, The bending moment M at position x m from the end of a simply supported beam of length L m carrying a uniformly distributed load of w Kn m-1 is given by

Find confidence interval for difference between two years : Find a 95% confidence interval for the difference between this year and last year in the mean number of units sold at all retail stores and interpret the results.

Compute the amount to be recorded as a leased asset : The appropriate interest rate for this lease is 12%. Compute the amount to be recorded as a leased asset and the associated lease liability.

Sales tracking and customer relations analyses : Analyse a set of data and write a brief report (in Microsoft Word), identifying and explaining your insights into the operation of "Ballarat Trade FairConsultancy".

What is the ph at the half-equivalence point : A weak monoprotic acid is exactly neutralized by 11.17mL of a standardized 0.1455M NaOH solution. If the Ka of the acid is 0.00084, what is the pH at the half-equivalence point.

Calculate the beginning inventory in process : Calculate the beginning inventory in process for (a) direct material equivalent units and (b) the conversion equivalent units if 10,000 whole units are identified and they are 40% completed.

User Account

All Pages