A college preparation academy claims that their 3-hour crash course may have an effect on students' SAT scores. A skeptical parent decided to perform research and administered the practice SAT tests to a sample of 33 students the day before and the day after the advertised 3-hour crash course. The following data with the means and standard deviations were obtained: After: 523 537 601 641 514 596 605 631 624 528 591 604 573 684 576 577 596 585 597 592 603 564 544 517 642 689 608 591 577 546 615 607 638 (Note: The average and the standard deviation of the data are respectively 591.39 points and 42.91 points.) Before: 571 701 544 603 713 692 684 673 596 513 557 683 679 676 645 605 690 670 641 642 576 562 657 635 565 606 583 507 582 651 639 606 628 (Note: The average and the standard deviation of the data are respectively 623.48 points and 55.45 points.) Difference: -48 -164 57 38 -199 -96 -79 -42 28 15 34 -79 -106 8 -69 -28 -94 -85 -44 -50 27 2 -113 -118 77 83 25 84 -5 -105 -24 1 10 (Note: The average and the standard deviation of the data are respectively -32.09 points and 71.18 points.) Use 1% level of significance to decide whether there is sufficient evidence that the mean practice SAT score after the crash course is the same as the mean practice SAT score before the crash course. Procedure: Assumptions: (select everything that applies) Normal populations Independent samples Population standard deviation are unknown but assumed equal Simple random samples The number of positive and negative responses are both greater than 10 for both samples Population standard deviations are known Sample sizes are both greater than 30 Population standard deviation are unknown Paired samples
A college preparation academy claims that their 3-hour crash course may have an effect on students' SAT scores. A skeptical parent decided to perform research and administered the practice SAT tests to a sample of 33 students the day before and the day after the advertised 3-hour crash course. The following data with the means and standard deviations were obtained:
After:
523 | 537 | 601 | 641 | 514 |
596 | 605 | 631 | 624 | 528 |
591 | 604 | 573 | 684 | 576 |
577 | 596 | 585 | 597 | 592 |
603 | 564 | 544 | 517 | 642 |
689 | 608 | 591 | 577 | 546 |
615 | 607 | 638 |
(Note: The average and the standard deviation of the data are respectively 591.39 points and 42.91 points.)
Before:
571 | 701 | 544 | 603 | 713 |
692 | 684 | 673 | 596 | 513 |
557 | 683 | 679 | 676 | 645 |
605 | 690 | 670 | 641 | 642 |
576 | 562 | 657 | 635 | 565 |
606 | 583 | 507 | 582 | 651 |
639 | 606 | 628 |
(Note: The average and the standard deviation of the data are respectively 623.48 points and 55.45 points.)
Difference:
-48 | -164 | 57 | 38 | -199 |
-96 | -79 | -42 | 28 | 15 |
34 | -79 | -106 | 8 | -69 |
-28 | -94 | -85 | -44 | -50 |
27 | 2 | -113 | -118 | 77 |
83 | 25 | 84 | -5 | -105 |
-24 | 1 | 10 |
(Note: The average and the standard deviation of the data are respectively -32.09 points and 71.18 points.)
Use 1% level of significance to decide whether there is sufficient evidence that the
Procedure:
Assumptions: (select everything that applies)
- Normal populations
- Independent samples
- Population standard deviation are unknown but assumed equal
- Simple random samples
- The number of positive and negative responses are both greater than 10 for both samples
- Population standard deviations are known
Sample sizes are both greater than 30- Population standard deviation are unknown
- Paired samples
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