TRACTOR SKIDDING HYPOTHESIS TESTING Forest engineers are interested in studying the skidding distances of tractors along a new road in a European Forest. The engineers collect data on a random sample of 12 tractors. The collected data (in meters) are: 350, 285, 574, 439, 295, 184, 261, 273, 400, 311, 141, 425. The average skidding distance for the sample of 12 tractors is 328.17 and the standard deviation is 118.46. Local loggers working on the road believe that the mean skidding distance of all tractors on this road is 325 meters. The engineers believe it is much greater than this. Conduct a hypothesis test based on the engineer’s belief. Conduct this hypothesis test at a significance level of .01. What is the value of the calculated test statistic? Use the rounded standard error from question 1 and round the final answer to the thousandths place.
Sol:
Ho:
Ha:
alpha=0.01
test statistic
t=xbar-mu/s/sqrt(n)
=(328.17 -325)/(118.46/sqrt(12)
t=0.093
the value of the calculated test statistic=t=0.093(rounded to 3 decimals)
degress of freedom=n-1=12-1=11
p value in excel is
=T.DIST.RT(0.093;11)
=0.463787893
=0..4639
p>0.01
Fail to reject Ho.
Accept Ho.
There is no sufficient statistical evidence at 1% level of significance to support the engineer's belief that
the mean skidding distance of all tractors on this road is greater than 325 meters.
TRACTOR SKIDDING HYPOTHESIS TESTING Forest engineers are interested in studying the skidding distances of tractors along...
TRACTOR SKIDDING HYPOTHESIS TESTING Forest engineers are interested in studying the skidding distances of tractors along a new road in a European Forest. The engineers collect data on a random sample of 12 tractors. The collected data (in meters) are: 350, 285, 574, 439, 295, 184, 261, 273, 400, 311, 141, 425. The average skidding distance for the sample of 12 tractors is 328.17 and the standard deviation is 118.46. Local loggers working on the road believe that the mean...
A group of researchers wants to estimate the true mean skidding distance along a new road in a certain forest. The skidding distances (in meters) were measured at 20 randomly selected road sites. These values are given in the accompanying table. Complete parts a through d. 490 350 198 285 407 573 438 545 380 0 297 430 180 261 273 404 311 314 141 a. Estimate the true mean skidding distance for the road with a 99% confidence interval...
Q.4 A group of researchers wants to estimate the true mean skidding distance along a new road in a certain forest. The skidding distances? (in meters) were measured at 20 randomly selected road sites. These values are given in the accompanying table. Complete parts a through d. 485 351 459 199 288 408 574 439 546 385 298 430 184 263 272 403 310 312 141 426 a. Estimate the true mean skidding distance for the road with a 90?%...
A group of researchers wants to estimate the true mean skidding distance along a new road in a certain forest. The skidding distances (in meters) were measured at 20 randomly selected road sites. These values are given in the accompanying table. Complete parts a through d. 490 348 455 199 290 405 570 439 545 385 299 435 183 261 275 402 311 313 141 426 a. Estimate the true mean skidding distance for the road with a 99% confidence...
A group of researchers wants to estimate the true mean skidding distance along a new road in a certain forest. The skidding distances (in meters) were measured at 20 randomly selected road sites. These values are given in the accompanying table. Complete parts a through d. 487 350 458 196 289 407 571 438 549 382 300 435 184 260 275 405 313 311 141 426 a. Estimate the true mean skidding distance for the road with a 95 %...