Question

1. Each of the following describes an association between two variables. Give a confounding variable that may help account for this association. (a) More ice cream sales have been linked to more deaths by drowning. (b) Air pollution is higher in places with a higher proportion of paved ground relative to grassy ground. 2. For each of the studies below indicate whether the data come from an experiment or an observational study. (a) A gene called ACTN3 encodes a protein which functions in fast-twitch muscles. Some people have a variant of this gene that cannot yield this protein. (So we might call the gene variant a possible non-sprinting gene.) To address the question of whether this gene is associated with sprinting ability, geneticists tested people from three different groups: world-class sprinters, world-class marathon runners, and a control group on non-athletes. In the samples tested, 6% of the sprinters had the gene variant, compared with 18% of the non-athletes and 24% of the marathon runners. This study suggests that sprinters are less likely than non-sprinters to the gene variant. (b) Do metal tags harm them? Scientists trying to tell penguins apart have several ways to tag the birds. One method involves wrapping metal strips with ID numbers around the penguins flipper, while another involves electronic tags. Neither the seems to physically harm the penguins. However, since tagged penguins are used to study all penguins, scientists wanted to determine whether the metal tags have any significant effect on the penguins. Data were collected over a 10-year span from a sample of 100 penguins that were randomly given either metal or electronic tags. This included information on the number of chicks, survival over the decade, and length of time on foraging trips.

Answer 1

* Please give positive rating - A Contounding Variable in an outside influence Pat Changes the effect of a dependent and independent Variale. It in an extra variable that you didn't account for. In summer season the sales of ice-cream generally increases, also in sumer season people tends to bath more. in pond/ river etc. In this example (Summer season can be a contounding Variable. In pared ground. Here tends to to te more traftic by vehicles. than in geassy ground, which is turn increases the air polloution.

Contounding Variable sol trattich can be in this study. 2. a) This in the study, because researder contools arrive on any example of experimental in experimental study, certain Varvable to conclusion. 6) This is the of example of observational study. In observational study, researchers Simpy Collect deitar tasedon what in geen and heard and simple inter based on data Collected.