CÂU HỎI 4 (SINGLECHOICE)
Data on oxide thickness of semiconductors are as follows: 425, 431, 416, 419, 421, 436, 418, 410, 431, 433, 423, 426, 410, 435, 436, 428, 411, 426, 409, 437, 422,428, 413, 416.
Which the following statement is (are) TRUE?
(i) The standard error of the mean is 1.85 Angstroms.
(ii) Standard deviation for the population is 9.08 Angstroms.
(iii) The mean oxide thickness is 423.33 Angstroms.
(iv) Our estimate for the median is 424 Angstroms.
Only (iii)
None of the other choices is correct
All off these.
Only (ii)
Only (i)
2 Đánh dấu
CÂU HỎI 5 (SINGLECHOICE)
Ít Đánh dấu
The compressive strength of concrete is normally distributed with p=1200 psi and σ-30. A random sample of n-9 specimens will have a sample mean diameter that falls in the interval from 1011 psi to 1230 psi.
What is the standard error of the sample mean?
400/3
30/9
10
the other choices is correct
