OCR MEI Paper 2 2022 June — Question 13

Exam BoardOCR MEI
ModulePaper 2 (Paper 2)
Year2022
SessionJune
TopicHypothesis test of binomial distributions
TypeInterpret test conclusion or error

13 Records from the 1950s showed that 35\% of human babies were born without wisdom teeth. It is believed that as part of the evolutionary process more babies are now born without wisdom teeth. In a random sample of 140 babies, collected in 2020, a researcher found that 61 were born without wisdom teeth. The researcher made the following statement.
"This shows that the percentage of babies born without wisdom teeth has increased from \(35 \%\)."
  1. Explain whether this statement can be fully justified.
  2. Conduct a hypothesis test at the \(5 \%\) level to determine whether there is any evidence to suggest that more than \(35 \%\) of babies are now born without wisdom teeth.