I need help with the questions that I have gotten incorrect

Research Question: Does the average quarterly cost of electricity differ for homes using LED lighting and homes using CFL lighting?

A feasibility study for sustainable energy is undertaken to compare energy costs in homes using LED (light emitting diode) bulbs and homes using CFL (compact fluorescent lamp) bulbs. 40 randomly selected three-bedroom-homes are selected and fitted with LED bulbs and energy costs are recorded for the following quarter. Another 40 randomly selected three-bedroom-homes are selected and fitted with CFL bulbs. Quarterly energy costs are also recorded for those houses.

Histogram of LEDcost Histogram otCFLcoa 12 14 1D Friar-my Fremoncy 4 CDII (3) D u IIIIIII I I I I 200250300350400450500 300 350 m 450 LED\" CFLcmit Answer the following questions by choosing the most correct option or typing the answer: 1. (1 mark) The most appropriate test for these data is: A two-sample t-test v v 2. (1 mark) The normality assumption seems reasonable because: the differences between LED and CFL energy costs may be drawn from a normal distribution. 3 I 3. (1 mark) The assumption of equal variance seems reasonable because: comparative boxplots suggest the spread in the two populations could be the same. 3 v 4. (2 marks) The absolute value of the test statistic is equal to (type your answer with 3 dp) 4.906 at 5. (1 mark) The degrees of freedom is equal to (type your answer as an integer) 78 v 6. (1 mark) The p-value is larger than 0.05 true = v 0 K 7. (2 marks) The test shows that the energy costs were significantly higher for houses fitted with CFL bulbs. A B Name Box CFLcost 2 319.47 423.91 3 330.87 335.72 4 311.87 321.1 5 401.16 330.43 6 388.43 405.06 353.3 370.78 8 425.42 349.04 9 347.83 399.19 10 316.44 347.67 11 243.32 355.73 12 400.12 442.84 13 409.19 373.63 14 252.98 328.44 15 394.19 395.68 16 313.63 385.2 17 430.76 401.58 18 311.81 406.55 19 375.28 401.6 20 304.03 320.05 21 331.76 441.35 22 369.36 410.4 23 318.77 422.17 24 325.27 315.97 25 335.32 352.71 26 383.41 383.63 27 361.43 398.43 28 317.19 326.82 29 489.08 302.7 30 382.58 411.43 31 362.45 287.35 32 367.63 359.58 33 271.13 433.78 34 353.18 329.65 35 378.45 354.27 36 423.86 399.38 37 282.13 363.64 38 384.19 333.6 39 373.01 427.37 40 296.82 300.87 41 326 420.56