A journalist wants to know how the 14420 residents of Ladysmith feel about a new bypass road. She interviews 72 shoppers at the local mall. Identify the population and the sample in this investigation.
Two methods are suggested to choose 13 apples from a crate of 238 to check for bruising. Method A: An inspector uses a random-number generator to pick 13 crate positions. Method B: An inspector only checks the 13 apples on the very top of the crate. Which method is RANDOM sampling? Give a reason.
A school wants Grade 8 opinions on the tuck shop menu. Every Grade 8 learner's name is entered into a computer, which randomly selects 20 of them. Is this a biased sample or a fair (representative) sample? Give a reason.
Two methods are suggested to choose 41 commuters to ask which airtime network they use. Method A: A researcher only asks her own family and neighbours. Method B: A researcher asks every 5th commuter boarding at 6 different taxi ranks. Which method is RANDOM sampling? Give a reason.
Two methods are suggested to select 7 learners from a class of 33 to interview about homework. Method A: The teacher picks the learners who always sit in the front row. Method B: The teacher writes all 33 names on paper, mixes them in a box, and draws out 7. Which method is RANDOM sampling? Give a reason.
A researcher wants to know the average screen time of the 1122 learners at a high school in Worcester. She surveys 29 learners waiting outside the hall. Identify the population and the sample in this investigation.
A radio station with 55 thousand listeners asks listeners to phone in their opinion on a new song. Is this a biased sample or a fair (representative) sample? Give a reason.
A clinic wants the average waiting time of the 3426 patients it sees in a month. It records the waiting time of 65 patients chosen at random. Identify the population and the sample in this investigation.
A researcher wants to know the average screen time of the 1213 learners at a high school in Mthatha. She surveys 37 learners waiting outside the hall. Identify the population and the sample in this investigation.
A shop in Mthatha wants to know which airtime network its customers prefer. Every 12th customer who enters the shop that day is asked. Is this a biased sample or a fair (representative) sample? Give a reason.
A radio station with 41 thousand listeners asks listeners to phone in their opinion on a new song. Is this a biased sample or a fair (representative) sample? Give a reason.
A manufacturer wants the average battery life of a shipment of 7086 cellphones. Technicians test 48 phones picked at random. Identify the population and the sample in this investigation.
