Financial analysts know that January credit card charges willgenerally be much lower than those of the month before. What aboutthe difference between January and the next? month? Does the trend?continue? The accompanying data set contains the monthly creditcard charges of a random sample of 99 cardholders. Complete parts?a) through? e) below.
January | February | |
|---|
902.74 | 641.04 | |
7212.18 | 4565.35 | |
4235.42 | 2270.56 | |
79.92 | 300.09 | |
4045.57 | 1377.72 | |
89.29 | ?120.74 | |
3289.59 | 1928.85 | |
2419.54 | 2609.97 | |
83.81 | 144.83 | |
6.42 | 392.85 | |
0.00 | 40.46 | |
564.69 | 295.63 | |
2712.23 | 848.62 | |
187.12 | 162.12 | |
3265.86 | 2412.45 | |
1523.59 | 956.31 | |
1359.23 | 38.03 | |
733.33 | 2656.79 | |
75.09 | 64.94 | |
70.29 | ?70.32 | |
634.53 | 1862.61 | |
1041.23 | 478.07 | |
553.08 | 994.64 | |
1016.27 | 774.54 | |
1304.94 | 3368.08 | |
249.39 | 5.52 | |
48.78 | 96.93 | |
872.34 | 890.89 | |
485.94 | 485.21 | |
616.52 | 1485.52 | |
1574.18 | 890.46 | |
422.34 | 391.43 | |
770.85 | 323.19 | |
56.53 | 0.00 | |
1486.78 | 2253.73 | |
495.28 | 390.19 | |
1064.88 | 1065.85 | |
510.65 | 131.33 | |
5637.68 | 4942.63 | |
5.49 | 5.51 | |
871.63 | 591.44 | |
1636.66 | 3364.19 | |
92.13 | 85.99 | |
669.34 | 1367.13 | |
829.32 | 280.85 | |
69.24 | 67.99 | |
830.54 | 1057.56 | |
2301.44 | 3317.76 | |
270.67 | 14.13 | |
210.42 | 160.52 | |
1012.36 | 519.35 | |
1044.96 | 2021.35 | |
298.64 | 635.44 | |
?29.99 | 0.00 | |
1634.61 | 393.34 | |
1731.93 | 1323.33 | |
0.00 | 65.16 | |
31.43 | 28.75 | |
4.95 | 77.15 | |
1088.69 | 892.78 | |
26.88 | 29.03 | |
120.31120.31 | 32.23 | |
2007.48 | 815.63 | |
291.31 | 779.47 | |
104.02 | 0.00 | |
53.01 | 66.25 | |
2842.52 | 1530.91 | |
675.47 | 293.45 | |
221.86 | 171.92 | |
37.79 | 4.78 | |
533.25 | 880.96 | |
1932.71 | 1063.55 | |
692.17 | 915.55 | |
6804.35 | 5941.41 | |
393.36 | 466.47 | |
1309.18 | 302.89 | |
796.21 | 497.02 | |
0.00 | 266.64 | |
1040.29 | 59.45 | |
565.12 | 206.62 | |
339.14 | 412.34 | |
5275.34 | 5324.54 | |
40.09 | 72.58 | |
43.39 | 38.45 | |
653.63 | 480.25 | |
1071.23 | 416.29 | |
2337.04 | 1787.19 | |
91.47 | 175.32 | |
1433.01 | 1107.78 | |
719.86 | 307.79 | |
28.61 | 24.19 | |
980.34 | 1216.35 | |
1576.18 | 1810.23 | |
0.00 | 468.24 | |
161.96 | 147.68 | |
494.32 | 1995.28 | |
534.11 | 935.24 | |
462.45 | 114.51 | |
1478.23 | 2093.37 |
?a) Build a regression model to predict February charges fromJanuary charges.
Feb=____+____Jan ?(Round to two decimal places as? needed.)
Check the conditions for this model. Select all of the truestatements related to checking the conditions.
A. All of the conditions are definitely satisfied.
B. The Linearity Condition is not satisfied.
C. The Randomization Condition is not satisfied.
D. The Equal Spread Condition is not satisfied.
E. The Nearly Normal Condition is not satisfied. ?
b) How? much, on? average, will cardholders who charged ?$2000in January charge in? February? ?$____ ?(Round to the nearest centas? needed.)
?c) Give a? 95% confidence interval for the average Februarycharges of cardholders who charged ?$2000 in January.
($___,$___) ?(Round to the nearest cent as? needed.) ?
d) From part? c), give a? 95% confidence interval for theaverage decrease in the charges of cardholders who charged ?$2000in January.
?($___,$___) (Round to the nearest cent as? needed.)
?e) What? reservations, if? any, would a researcher have aboutthe confidence intervals made in parts? c) and? d)? Select all thatapply.
A. The residuals show increasing? spread, so the confidenceintervals may not be valid.
B. The residuals show a curvilinear? pattern, so the confidenceintervals may not be valid.
C. The data are not? linear, so the confidence intervals are notvalid.
D. The data are not? independent, so the confidence intervalsare not valid.
E. A researcher would not have any reservations. The confidenceintervals are valid. Click to select your answer(s).
