The manager of gas station would like to estimate the mean number of litres (L) of gasoline sold to his customers. Assume the number of litres sold follows the normal distribution with a standard deviation of 40 L. From his records, he selects a random sample of 29 sales and finds the mean number of litres sold is 89.

Use these tables to determine thez-value(s) or t-value(s).

(Round z-values to 2 decimals and t-values to 3 decimals)

a. What is the point estimate of the population mean?

The point estimate of the population mean is litres.(Round it to the nearest whole number.)

b. Explain what distribution you will use and why.

(Click to select) z distribution because the population standard deviation is known. t distribution because the population standard deviation is unknown. z distribution because the sample mean is known. t distribution because the sample mean is unknown. z distribution because the the confidence interval is for a population proportion. t distribution because the the confidence interval is for a population proportion.

c. For a 98% confidence interval, what is the value zort(depending on your answer in b.)?

The value ofzortis .

d. Develop a 98% confidence interval for the population mean.

The 98% confidence interval for the population mean is between and .(Round each to 3 decimal places.)

e.Interpret the meaning of part (d).

If 100 such intervals were determined, the (Click to select) sample mean population variance sample statistic population mean sample variance would appear in about of those intervals.

X-value

Areas under the Normal Curve Example: If z = 1.96, then P(0 to z) = 0.4750 0.4750 0 1.96 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 108 0.09 0.0 0.0000 0.0040 0.0080 0.0120 0.0160 0.0199 0.0239 0.0279 0.0319 0.0359 0.1 0.0398 0.0438 0.0478 0.0517 0.0557 0.0596 0.0636 0.0675 0.0714 0.0753 0.2 0.0793 0.0832 0.0871 0.0910 0.0948 0.0987 0.1026 0.1064 0.1103 0.1141 0.3 0.1179 0.1217 0.1255 0.1293 0.1331 0.1368 0.1406 0.1443 0.1480 0.1517 0.4 0.1554 0.1591 0.1628 0.1664 0.1700 0.1736 0.1772 0.1808 0.1844 0.1879 0.5 0.1915 0.1950 0.1985 0.2019 0.2054 0.2088 0.2123 0.2157 0.2190 0.2224 0.6 0.2257 0.2291 0.2324 0.2357 0.2389 0.2422 0.2454 0.2486 0.2517 0.2549 0.7 0.2580 0.2611 0.2642 0.2673 0.2704 0.2734 0.2764 0.2794 0.2823 0.2852 0.8 0.2881 0.2910 0.2939 0.2967 0.2995 0.3023 0.3051 0.3078 0.3106 0.3133 0.9 0.3159 0.3186 0.3212 0.3238 0.3264 0.3289 0.3315 0.3340 0.3365 D.3389 1.0 0.3413 0.3438 0.3461 0.3485 0.3508 0.3531 0.3554 0.3577 0.3599 0.3621 1.1 0.3643 0.3665 0.3686 0.3708 0.3729 0.3749 0.3770 0.3790 0.3810 0.3830 1.2 0.3849 0.3869 0.3888 0.3907 0.3925 0.3944 0.3962 0.3980 0.3997 0.4015 1.3 0.4032 0.4049 0.4066 0.4082 0.4099 0.4115 0.4131 0.4147 0.4162 0.4177 1.4 0.4192 0.4207 0.4222 0.4236 0.4251 0.4265 0.4279 0.4292 0.4306 0.4319 1.5 0.4332 0.4345 0.4357 0.4370 0.4382 0.4394 0.4406 0.4418 0.4429 0.4441 1.6 0.4452 0.4463 0.4474 0.4484 0.4495 0.4505 0.4515 0.4525 0.4535 D.4545 1.7 0.4554 0.4564 0.4573 0.4582 0.4591 0.4599 0.4608 0.4616 0.4625 0.4633 1.8 0.4641 0.4649 0.4656 0.4664 0.4671 0.4678 0.4686 0.4693 0.4699 0.4706 1.9 0.4713 0.4719 0.4726 0.4732 0.4738 0.4744 0.4750 0.4756 0.4761 0.4767 2.0 0.4772 0.4778 0.4783 0.4788 0.4793 0.4798 0.4803 D.4808 0.4812 0.4817 2.1 0.4821 0.4826 0.4830 0.4834 0.4838 0.4842 0.4846 0.4850 0.4854 0.4857 2.2 0.4861 0.4864 0.4868 0.4871 0.4875 0.4878 0.4881 0.4884 0.4887 0.4890 2.3 0.4893 0.4896 0.4898 0.4901 0.4904 0.4906 0.4909 0.4911 0.4913 0.4916 2.4 0.4918 0.4920 0.4922 0.4925 0.4927 0.4929 0.4931 0.4932 0.4934 0.4936 2.5 0.4938 0.4940 0.4941 0.4943 0.4945 0.4946 0.4948 0.4949 0.4951 0.4952 2.6 0.4953 0.4955 0.4956 0.4957 0.4959 0.4960 0.4961 0.4962 0.4963 0.4964 2.7 0.4965 0.4966 0.4967 0.4968 0.4969 0.4970 0.4971 0.4972 0.4973 0.4974 2.8 0.497 4 0.4975 0.4976 0.4977 0.4977 0.4978 0.4979 0.4979 0.4980 0.4981 2.9 0.4981 0.4982 0.4982 0.4983 0.4984 0.4984 0.4985 0.4985 0.4986 D.4986 3.0 0.4987 0.4987 0.4987 0.4988 0.4988 0.4989 0.4989 0.4989 0.4990 0.4990Student's & Distribution - 0 - 0 Two-tailed test Left-tailed test Right-tailed test Confidence interval Confidence Intermis, C Level of Significance for One-Tailed Test, a Level of Significance for One- Triled 0.05 D.10 0/05 0.025 0 005 Level of Significance for Two-Tailed Test, a Level of Significance for Two-failed 10 05 0.10 2.719 12 706 13 657 31.589 2.076 2.715 3 574 4 303 2.712 3.586 32182 4541 12:124 2.074 3.747 2083 2.426 2.708 3.958 1.533 2.132 2778 1012 8.861 3021 2.423 2.704 3.561 2015 21571 41 2.421 24701 2447 1.141 2:018 2418 1.415 2:365 5.400 42 1302 2017 2.416 2.805 3502 1.397 1.860 2:308 2.806 5.041 43 1302 1.681 2.821 3.250 4.781 44 1-301 1.680 2015 2414 3526 1.383 1.833 2 282 2.764 3.1080 4 587 45 1.301 2014 2412 3.520 1.372 1.812 2 228 2718 4.437 1-300 2013 2410 3515 1.796 2:201 1-300 1.678 2:012 3510 1.712 2.170 2.681 1221 1.677 2.017 2./642 1.350 1.771 2.160 2.850 1012 80841 2010 2.406 1.800 1.345 1.781 2.145 4.1.40 2003 3.498 2131 2941 4073 1.210 1.341 1.753 2802 1 492 1.397 1.7:46 2.120 2421 4.014 51 1.675 2008 1.675 2 007 2-400 1.740 2110 2.567 1.734 2:101 3422 53 1.298 1.674 2.006 2 309 2.872 2.003 1.480 2:093 3.478 3.450 1.217 2004 1.325 1.7:25 3473 2.518 56 1 247 1.673 2.345 1.323 1,721 2:431 3.419 2 39 3470 1.717 2074 2:50 2.819 3.792 1.672 2:500 2.807 58 1.296 1.672 2002 1.71 1.318 1.711 2:064 2.402 2 797 59 1.671 2:001 3.460 1.314 1.708 2.485 2.787 1.725 60 1.218 1671 2.000 125 2.070 1.706 2479 2 779 3.707 1.670 1.909 3 494 1.31 1.703 2771 3.890 2:467 2 701 3474 63 1.680 2 347 143 1.313 1.701 3 449 2045 2.462 2:756 1.210 1.609 2:386 2.855 1.311 1.685 2.854 2:042 2.457 2.750 1 20 1.997 1.30 2.453 2 74 1431 66 1.907 3 447 3037 2:449 273 3.427 3430 2:445 2731 3411 2:012 2:441 2:720 3.801 1.891 1435 2 030 2:438 Confidence Interval, C Confidence Internals, e 95% Level of Significance for One-Called Test 0/025 0.01 0.10 0.10 1.20 1.662 2.509 27632 1.20 2:360 1.293 2.379 .293 2:379 1.429 3.401 2 378 91 2631 .293 3 475 92 2:630 1.793 2:317 2:630 665 2:376 2502 1 301 2.629 1.291 2.376 2401 3.421 95 2.375 3.420 2.658 2.374 3.418 14290 1.861 1.861 2 627 2:374 2639 3 416 97 FLO SUITE FFEF FEFRE 1.292 GG4 1.230 1.661 2.373 3 415 1 210 1.660 .664 3413 1.660 2.626 564 2.373 2631 2.372 3.412 1.920 2.958 2617 1373 1.292 2.372 2:636 3.410 120 LESE 1.977 2.353 2811 2:371 2:635 3.809 1.654 1.975 2.350 2 807 3.352 2:347 2:370 2634 3.507 1.973 1845 1.863 3 206 1653 1.972 2.345 2.601 3 340 561 2 370 2 326 2.576 1291 1.291 2.309