Sales 2015 Sales 2016

403.79 440.47

485.68 514.69

422.27 460.52

423.66 451.47

518.8 593.29

524.65 516.11

443.89 418.84

539.1 545.92

436.02 418.74

400.32 394.67

555.69 665.72

500.76 534.01

393.07 386.68

500.35 471.28

509.7 565.39

386.71 424.21

614.64 664.62

535.05 582.11

416.03 391.76

584.33 599.27

361.4 371.12

497.47 473.85

384.64 452.33

547.28 575.16

520.62 701.9

457.05 426.66

575.29 635.54

533.18 522.68

342.88 387.11

456.17 480.21

534.14 583.66

455.63 484.6

431.84 416.01

448.85 521.08

545.08 566.59

380.85 390.51

387.3 394.46

445.12 440.82

401.79 437.41

514.16 548.34

347.91 380.7

553.55 534.79

547.58 507.05

433.28 412.05

556.49 527.3

359.3 430.25

360.19 439.93

433.01 409.61

496.31 547.36

419.87 376.82

374.66 457.59

558.69 534.73

523.85 572.94

539.95 584.3

438.09 453.18

430.91 502.27

385.21 398.07

371.31 431.55

546.77 621.25

414.15 443.76

469.58. 442.99

494.9 486.81

414.93 376.88

476.46 512.04

423.52 387.99

476.08 508.58

572.92 618.51

470.97 459.61

356.35 443.1

470.74 474.41

650.18 677.01

369.75 340.93

505.52 486.21

593.03 586.01

441.94 472.25

540.02 591.83

487.51 402.41

340.71 381.56

453.56 441.36

472.47 503.27

508.5 551.73

399.35 391.41

501.17 486.98

456.28 393.74

469.76 486.61

442.07 480.8

The accompanying data give the sales volume (in dollars per square foot) for 86 retail outlets specializing in women's clothing in 2015 and 2016. Did sales change by a statistically signicant amount from 2015 to 2016? Use on = 0.05. Click the icon to view the data table. Let [.11 be the mean sales volume in 2015 and let p2 be the mean sales volume in 2016. The 95% condence interval for pd = p1 - p2 is D to D dollars per square foot. (Round to two decimal places as needed.)