Height of group of 20 boys aged 10 years was 140 ± 13 cm and 20 girls of same age was 135 cm ± 7 cm. To test the statistical significance of difference in height, test applicable is -
X2
Z
t
F
Student’s t-test:

– Paired Student’s t-test: Comparing means (± SD) in paired data (in same group of individuals before and after an intervention)
– Unpaired Student’s t-test: Comparing means (± SD) in two different group of individuals
– Z-test: Is a variant of student’s t-test which is used when sample size is > 30.
In the given question, mean ± SD of 20 boys (140 ± 13 cm) and 20 girls (135 cm ± 7cm) of the same age are compared, Thus most appropriate statistical test of significance would be Unpaired Student’s t-test.