Determine the critical value of z given 70% confidence level

1.20

1.28

1.36

1.48

A researcher calculated a mean of 80 from his research data. If the standard deviation was 16 and his degree of freedom was 19, what sample size did the researcher use?

18

19

20

21

Sampled mean is 90. The given standard deviation is 36 and the sample size is 16. Determinate the confidence interval (limits) at 99% confidence level.

75.15 to 104.85

72.36 to 107.64

66.78 to 113.2

None of the above

The scores obtained in Business and Economic Statistics examination sample are given as follows: 70 80 60 90 100 and 80. What is the researcher's point estimate?

6

70

80

None of the above

Given the scores of 70, 80, 60, 90, 100 and 80. What is the researcher's standard deviation?

12.44

13.64

14.14

15.25

Given the scores of: 70, 80, 60, 90, 100 and 80. What should the researcher's critical value be at 99% confidence level

Table 3 Areas of the Standard Normal Distribution The entries in this table are the probabilities that a random variable with a standard normal distribution assumes a value between 0 and z; the proba- bility is represented by the shaded area under the curve in the accompany- ing figure. Areas for negative values of z are obtained by symmetry. 0 Second Decimal Place in z 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 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 0.3389 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 0.4545 1.7 0.4554 0.4564 0.4573 0.4582 0.4591 0.4599 0.4608 0.4616 0.4625 0.4633Table 3 Areas of the Standard Normal Distribution The entries in this table are the probabilities that a random variable with a standard normal distribution assumes a value between 0 and z; the proba- bility is represented by the shaded area under the curve in the accompany- ing figure. Areas for negative values of z are obtained by symmetry. 0 Second Decimal Place in 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 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 0.3389 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 0.4545 1.7 0.4554 0.4564 0.4573 0.4582 0.4591 0.4599 0.4608 0.4616 0.4625 0.4633Values of t for Selected Probabilities Copy 0.05 05. 1=.-1,8125 -=1.8125 Probabilites (Or Areas Under t-Distribution Curve) Conf. Level 0.1 0.3 0.5 0.7 0.8 0.9 0.95 0.98 0.99 One Tail 0.45 0.35 0.25 0.15 0.1 :0.05 0.025 0.01 0.005 Two Tails 0.9 0.7 0.5 0.3 0.2 0.14 0.05 0.02 0.01 d. f. Values of t 0.1584 0.5095 1.0000 1.9626 3.0777 6.3137 12.7062 31.8210 63.6559 0.1421 0.4447 0.8165 1.3862 1.8856 2.9200 4.3027 6.9645 9.9250 0.1366 0.4242 0.7649 1.2498 1.6377 2.3534 3.1824 4.5407 5.8408 0.1338 0.4142 0.7407 1.1896 1.5332 2.1318 2.7765 3.7469 4.6041 0.1322 0.4082 0.7267 1.1558 1.4759 2.0150 2.5706 3.3649 4.0321 0.1311 0.4043 0.7176 1.1342 1.4398 1.9432 2.4469 3.1427 3.7074 0.1303 0.4015 . 0.7111 1.1192 1.4149 1.8946 2.3646 2.9979 3.4995 0.1297 0.3995 0.7064 1.1081 1.3968 1.8595 2.3060 2.8965 3.3554 0.1293 0.3979 *0.7027 1.0997 1.3830 1.8331 2.2622 2.8214 3.2498 10 0.1289 0.3966 0.6998 1.0931 .. 1.3722 18125 2.2281 2.7638 3.1693 11 0.1286 0.3956 0.6974 1.0877 1.3634 1.7959 2.2010 2.7181 3.1058