​In a study of parents’ perceptions of their children’s size,
researchers Kaufman et al. (Current Biology, 2013) asked parents to
estimate their youngest child’s height. The researchers
hypothesized that parents tend to underestimate their youngest
child’s size because the youngest child is the baby of the family
and everybody else is the family appears bigger compared to the
baby. The researchers also surveyed a sample of 29 parents about
their eldest child’s height. The parents overestimated their eldest
child’s height by 0.3 cm, on average; the standard deviation for
the difference in actual heights and estimated heights was 4.8 cm
without strong skewness in the data. Incorrect answer. Your answer
is incorrect. Try again. Is there evidence that parents tend to
either over- or under-estimate eldest children’s heights? Carry out
a theory-based test using an appropriate applet or statistical
software. Find and report a p-value as well as a standardized
statistic. Round the test statistic to 2 decimal places, e.g. 5.83,
and the p-value to 4 decimal places, e.g. 0.0583. t =Entry field
with incorrect answer now contains modified data , p-value = Entry
field with incorrect answer now contains modified data (two-sided
test) Incorrect answer. Your answer is incorrect. Try again. Using
an appropriate applet or statistical software, find a 95%
confidence interval for the difference.​ Round your answers to 2
decimal places, e.g. 5.83. Confidence interval = (Entry field with
incorrect answer now contains modified data , Entry field with
incorrect answer now contains modified data ) Correct answer. Your
answer is correct. We have found a very significant difference in
the actual and estimated average heights of eldest children by
their parents, with parents, on average, estimating the height of
their oldest child between $ll1 and $ul cm more than actual height.
Entry field with correct answer True False Incorrect answer. Your
answer is incorrect. Try again. What assumption do you have to make
about the data in order for the validity conditions of the
appropriate theory-based test to be satisfied? Entry field with
incorrect answer now contains modified data The sample size is
larger. The sample size is smaller. There is not strong skewness in
the distribution of differences in actual and estimated heights.
There is strong skewness in the distribution of differences in
actual and estimated heights.
