The sales manager at a certain company is trying to decide how much of the budget to allocate for sales personnel for the upcoming year. Typically,...

The sales manager at a certain company is trying to decide how much of the budget to allocate for

sales personnel for the upcoming year. Typically, sales costs run about 15% of Sales. To help develop an

estimate, the sales manager studies sales (in millions $) during the past 2 years at company X, which are

given in the table below.

Month Sales

January 390

February 205

March 270

April 245

May 320

June 290

July 299

August 345

September 326

October 355

November 359

December 371

January 368

February 358

March 345

April 380

May 391

June 403

July 410

August 430

September 410

October 415

November 310

December 450

a) Use SPSS to display histogram for sales. Use class widths of 25 and begin with 225. The class

endpoints should be 225, 250, 275, ..., 450.

b) show a time plot for this data. The horizontal axis should indicate the month.