https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf en-us 2023-10-08 09:31:46 UTC 2023-10-20 05:12:20 UTC hello@padlet.com https://padlet.net/icons/png/1f5a5.png zhuangxinrui https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739174824 A hotel has 30 floors with 40 rooms per floor. The rooms on one side of the hotel face the water, while rooms on the other side face a golf course. There is an extra charge for the rooms with a water view. The hotel manager wants to survey 120 guests who stayed at the hotel during a
convention about their overall satisfaction with the property.
1.
(a)describe how to conduct a stratified random sample.
(b) Explain why choosing a stratified random sample might be preferable to an SRS in this case.
2.
(a)describe how to conduct a cluster sample.
(b) Why might a cluster sample be a simpler option?]]> 2023-10-10 03:27:00 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739174824 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739581089 2023-10-10 09:01:08 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739581089 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739823341 1. a. Name all the rooms with two strata: water 1-600 and golf 1-600, for those who can see water and golf field respectively. Then pick 30 samples in each stratum by reading off the three-digit-number group in Table D. While selecting, ignore those numbers that are higher than 600, equal to 000, and repeat. Calculate the mean satisfaction of these dwellers and repeat these steps five times.  
1. b. Since the satisfaction can vary greatly between the dwellers of the room on the golf course's side and those on the water's side, the result of choosing too many dwellers from one of the two sets can deviate strongly from the true mean. 
2. a. Let each floor of the hotel become a cluster, naming each of them from 01-30. Then pick 3 clusters by reading off the two-digit-number group in Table D. While selecting, ignore those numbers that are higher than 30, equal to 00, and repeat. Calculate the mean satisfaction of these dwellers and repeat this process five times. 
2. b. Because there are large differences between the samples that are in the same cluster, it can lead to deviated results if rooms from any of the two sides are accidentally chosen too many. ]]> 2023-10-10 12:11:28 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739823341 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739974463 1(a) Assign room numbers with toe strata: water view1-600 and golf view 1-600. Reading off a three digit group at a time from table d and pick 30 samples from each strata, ignores any over 600 and repeated groups.
(b) Guests' satifaction would be greatly affected by the view of room. Choosing too many rooms from either views would lead to inaccurate result.
2(a) Floor would be the cluster. Assign each floor 01 to 30. Reading off a two digit group at a time from table d and pick 3 samples from each floor,ignores any over 30 and repeated numbers.
(b)  Guests' satifaction would be greatly affected by the height and view of room. Choosing too many rooms from one floor would lead to inaccurate result. ]]> 2023-10-10 13:39:50 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2739974463 John0457 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2741711174 1.(a):Divide the side facing the water and the side facing the golf course into two strata. Then name all the rooms: water 001-600 and golf 001-600. Choose 30 samples from each floor(why?) by using Table D that read off the three-digit-number group in the Table D, ignore the repeat numbers and the numbers higher than 600. Calculate the mean satisfaction of dwellers, then repeat this process five times.
(b): In SRS, it is possible to get the number that too extreme, it will make a big effect to the result of case. Stratified can avoid this situation.
2.(a): Name all the floors with 30 cluster: 01-30. Then choose 3 clusters by reading-off the two-digit-number group in Table D. Ignore the repeat number and the numbers higher than 30. Calculate the mean satisfaction of dwellers, then repeat the process five times.
(b): Because the differences between cluster samples are small, and it is convenient to get the result of case.]]> 2023-10-11 12:21:53 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2741711174 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2744825621 2023-10-13 07:10:45 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2744825621 zhuangxinrui https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752249161 Dr. Linda Stern and her colleagues recruited 132 obese adults at the Philadelphia Veterans Affairs Medical Center in Pennsylvania. Half the participants were randomly assigned to a low-carbohydrate diet and the other half to a low-fat diet. Researchers measured each participant’s change in weight and cholesterol level after six months and again after one year. 
1.Explain how each of the four principles of experimental design was used in this study. 

2.Describe a completely randomized design for this experiment. Write a few sentences describing how you would implement your design. ]]> 2023-10-18 07:33:36 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752249161 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752634198 1. 
comparison: one group eats a low-carbohydrate diet while the other eats a low-fat diet. 
random assigning: half of the subjects are assigned randomly to one group, while the remaining ones are assigned to the other. 
control variable: ]]> 2023-10-18 12:45:01 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752634198 3374360732 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752764424 1.
comparison:compare one group take low-carbohydarate diet and other group take low-fat diet
random assignment: participants are randomly assigned to two group.
replication:measure the level after six months and one years,and choose 132 adults.


]]> 2023-10-18 14:00:17 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752764424 John0457 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752807398 1: Random assignment: The experiment choose 132 people at random.
Comparison: These people are divided them into two groups, then it compare these groups.
Control: Half the participants were randomly assigned to a low-carbohydrate diet and the other half to a low-fat diet, they are divided into two different conditions, so that we can control the effect of some variable.
replication: The experimental units are enough to make the experiment, the participants are choosed at random and the effect of some variable are control.

2: ]]> 2023-10-18 14:23:44 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2752807398 https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2754068869 2023-10-19 06:39:27 UTC https://padlet.com/zhuangxinrui/z40d4ovyubzxx2vf/wish/2754068869