A sample of 30 observations was collected that used a standard UNIX program call
ID: 3181191 • Letter: A
Question
A sample of 30 observations was collected that used a standard UNIX program called "ping" to measure the time (ms) taken to reach, and receive a reply from, another computer on the Internet. a. The sample mean time is (2DP), sample standard deviation is (4DP); b. Set up a 95 percent confidence interval estimate of the population average time (ms) taken to reach, and receive a reply from, another computer on the Internet. degree of freedom is; critical value t= (4DP)' lower limit of CI for mean is (2DP); upper limit of CI for mean is (2DP). c. Set 95 percent confidence interval estimate of the population standard deviation of the time (ms) taken to reach, and receive a reply from, another computer on the Internet. lower critical value of chi-square is (3DP); upper critical value of chi-square is (3DP); lower limit of CI for standard deviation is (2DP); upper limit of CI for standard deviation is (2DP).Explanation / Answer
a)
b)deree of freedom =n-1=29
std error =std deviation/(n)1/2 =47.172
critical value for 29 df and 95% CI, t=2.0452
hence lower limit =mean -t*Std error =332.36
upper limit =mean -t*Std error =525.31
c) for 95% CI, lower critrval value =16.047
upper critical value =45.722
lower limit of SD =205.77
upper limit =347.34
X 1450 310 222 680 299 157 202 525 568 447 129 253 406 331 644 822 461 292 204 396 684 517 322 536 343 259 526 288 330 262 mean 428.8333 std deviation 258.3741