I am able to calculate the mean, model, std deviation for following question but need an analysis of the answer and the relevant graphs I can add with the solution

The Cell Phone Case: Reducing Cellular Phone Costs

Rising cell phone costs have forced companies having large numbers of cellular users to hire services to manage their cellular and other wireless resources. These cellular management services use sophisticated software and mathematical models to choose cost-efficient cell phone plans for their clients. One such firm, mindWireless of Austin, Texas, specializes in automated wireless cost management. According to Kevin Whitehurst, co-founder of mindWireless, cell phone carriers count on verageusing more minutes than one's plan allowsand underageusing fewer minutes than those already paid forto deliver almost half of their revenues.3 As a result, a company's typical cost of cell phone use can be excessive18 cents per minute or more. However, Mr. Whitehurst explains that by using mindWireless automated cost management to select calling plans, this cost can be reduced to 12 cents per minute or less. In this case we consider a bank that wishes to decide whether to hire a cellular management service to choose its employees' calling plans. While the bank has over 10,000 employees on many different types of calling plans, a cellular management service suggests that by studying the calling patterns of cellular users on 500-minute-per-month plans, the bank can accurately assess whether its cell phone costs can be substantially reduced. The bank has 2,136 employees on a variety of 500-minute-per-month plans with different basic monthly rates, different overage charges, and different additional charges for long distance and roaming. It would be extremely time consuming to analyse in detail the cell phone bills of all 2,136 employees. Therefore, the bank will estimate its cellular costs for the 500-minute plans by analysing last month's cell phone bills for a random sample of 100 employees on these plans. When the random sample of 100 employees is chosen, the number of cellular minutes used by each sampled employee during last month (the employee's cellular usage) is found and recorded. The 100 cellular-usage figures are given in Table

75

485

37

547

753

93

897

694

797

477

654

578

504

670

490

225

509

247

597

173

496

553

0

198

507

157

672

296

774

479

0

822

705

814

20

513

546

801

721

273

879

433

420

521

648

41

528

359

367

948

511

704

535

585

341

530

216

512

491

0

542

562

49

505

461

496

241

624

885

259

571

338

503

529

737

444

372

555

290

830

719

120

468

730

853

18

479

144

24

513

482

683

212

418

399

376

323

173

669

611

Analyse the data find descriptive statistics measures and help the company to take a decision.