Can you help me with Part D of 6.38? I did everything except Part D. I included the z-table, if possible.
6.38 Cost of unleaded fuel. According to the American Automobile Association (AAA), the average cost of a gal- lon of regular unleaded fuel at gas stations in May 2014 was $3.65 (AAA Fuel Gauge Report). Assume that the standard deviation of such costs is $.15. Suppose that a ran- dom sample of n = 100 gas stations is selected from the population and the cost per gallon of regular unleaded fuel is determined for each. Consider x, the sample mean cost per gallon. a. Calculate My and Ox. b. What is the approximate probability that the sample has a mean fuel cost between $3.65 and $3.67? c. What is the approximate probability that the sample has a mean fuel cost that exceeds $3.67? d. How would the sampling distribution of x change if the sample size n were doubled from 100 to 200? How do your answers to parts b and c change when the sample size is doubled?\f\fShaded area = Pr(Z S z) TABLE 1 Standard normal curve areas 0 07 .08 .09 .00 .01 .02 .03 .04 .05 .06 -3.4 0003 6003 0003 0002 .0003 0003 0003 0003 0003 0003 0003 -3.3 .000S 0004 0004 0005 0005 0004 0004 0004 0004 .0005 0005 0005 -3.2 0007 0007 0006 0006 0006 0006 .0006 -3.1 0010 0009 0008 0007 .0007 0009 0009 .0008 0008 .0008 -3.0 0010 0013 .0013 .0013 0012 .0012 001 .0011 0011 .0010 -2.9 .0019 .0014 .0016 0016 0015 .0015 0014 0018 0018 .0017 -2.8 0026 0025 0020 0019 0024 .0023 0023 .0022 002 .002 - 2.7 .00351 0034 0033 0031 0029 Q028 0027 0026 .0032 .0030 -2.6 0047 0045 0044 .0043 0041 .0040 0039 0038 .0037 0036 -2.5 0062 0060 0059 .0049 0057 0055 .0054 .0052 0051 .0048 -2.4 0082 0080 0078 0075 0073 .0071 .0069 0068 .0066 .0064 -2.3 0107 0104 0102 0099 0096 0094 .0091 0089 0087 -2.2 013 .0136 0132 .0129 0125 0122 .0119 0116 .0113 0110 -2.1 017 0174 .0170 0166 0162 0158 .0154 .0150 0146 0143 -2.0 0228 0222 0217 0212 0207 .0202 0197 .0192 0188 .0183 - 1.9 .0287 0281 .0274 0268 .0262 0256 0250 0244 0239 0233 -1.8 0359 .0351 .0344 0336 .0329 0322 0314 0307 0301 .0294 - 1.7 0446 0436 .0427 .0418 .0409 .0401 0392 0384 0375 .0367 - 1.6 .0548 .0537 0526 0516 .0505 .0495 0485 0475 .0465 .0455 -1.5 .0668 0655 .0643 0630 .0618 0606 .0594 0582 .0571 0559 -1.4 0808 0793 0778 1764 .0749 0735 .072 0708 0694 0681 -1.3 0968 .0951 0934 0918 .0901 .0885 .0869 0853 0838 0823 -1.2 .1151 113 1112 1093 .1075 .1056 .1038 .1020 1003 0985 -1.1 .1357 1335 .1314 1292 1271 .1251 1230 .1210 1190 1170 -1.0 .1587 .1562 .1539 . 1515 .1492 1469 1446 1423 .1401 1379 -.9 .1841 1814 1788 1762 1736 1711 1685 1660 1635 .1611 - .8 .21 19 2090 .2061 2033 .2005 1977 1949 1922 .1894 -1867 - 7 .2420 .2389 .2358 2327 2296 2266 2236 2206 .2177 .2148 -. 6 2743 270 :2676 2643 .2611 2578 .2546 2514 .2483 2451 -.5 .3085 3050 .3015 2981 2946 2912 2877 .2843 2810 2776 - .4 3446 3409 .3372 .3336 .3300 .3264 3228 3192 .3156 i : .3821 378 .3745 3707 .3669 .3632 .3594 .3121 3557 .3520 - . 2 4207 4168 4129 .4090 4052 4013 3974 .3483 3936 4483 4443 4404 3897 -1 .4602 4562 4522 4364 3859 4325 4286 -.0 .5000 4960 .4920 .4880 .4840 4801 4761 .4721 4247 .4681 4641 Z Area -3.50 00023263 -4.00 00003167 -4.50 00000340 -5.00 .00000029 00000000
