A company has been producing steel tubes of mean inner diameter of 3 cm. A sample of 17 tubes gives an inner diameter of 3.01 cm and a standard deviation of 0.064. Then the value of t-test statistic is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 0.625
Here \( \mu=3 \), \( \bar{x}=3.01 \), n = 17, and the sample standard deviation is s = 0.064. When s is the standard deviation of the sample itself (divisor n), the t statistic for a single mean is
\( \displaystyle t=\frac{\bar{x}-\mu}{s/\sqrt{n-1}} \)
\( \displaystyle t=\frac{3.01-3}{0.064/\sqrt{16}} \)
\( \displaystyle t=\frac{0.01}{0.016} \)
\( \displaystyle t=0.625 \)