A statistics instructor asks each student in his classes to report how much the student spent on textbooks for the semester. The figures reported by students are shown below. 380 296 404 412 484 224 456 492 384 688 408 384 528 424 300 500 456 416 476 656 472 428 560 592 428 600 504 336 276 564 524 372 480 488 760 528 480 432 448 524 472 524 392 444 664 608 336 440 296 556 416 356 652 520 532 348 452 584 340 472 404 544 464 444 560 432 380 468 308 440 616 428 448 424 556 632 496 252 496 256 716 484 500 444 616 656 324 444 440 640 360 488 504 408 356 620 448 448 484 508 364 572 408 580 456 256 236 488 308 636 488 320 508 472 636 396 436 388 348 596 360 484 576 512 472 368 500 312 464 596 288 536 388 396 496 720 344 496 504 404 572 448 176 668

Treat the data above as POPULATION data. 1 The mean expenditure on textbooks by all students is:

2. The variance of the expenditure on textbooks by all students is:

The instructor takes a random sample of size from the population data and obtains the following sample data: x 344 408 556 620 392 440

3. The sample mean is:

4. The sample variance is

5. If we take random samples of size n = 6 from this population, the number of possible samples is:

6. The expected value (mean) of sample means is equal to:

7. The variance of sample means is:

8. The sample standard deviation is,

9. The standard error of the sample mean is,