Question

data: fill in the chart as appropriate. you will not have data for every single species of prey. remember, owls spit out 2.5 pellets/day on average.

prey	length (cm)	number found	number eaten per day	number eaten per week	number eaten per year
mole	12 to 14
shrew	8
rat	40		2.5	17.5	910
bird	15
total

Explanation:

Step1: Analyze Rat's "Number eaten per week"

We know the number eaten per day for Rat is 2.5. To find per week, multiply by 7 (days in a week). So \( 2.5\times7 = 17.5 \), which matches the given 17.5.

Step2: Analyze Rat's "Number eaten per year"

Assume a year has 365 days. Multiply per day (2.5) by 365: \( 2.5\times365 = 912.5 \), but the written value is 90 (maybe a typo or simplified, but following the chart's logic). For other prey, we can use the same method (per day × days in period). For example, if we take Shrew: need to find per day, week, year. But since the problem is about filling the chart, using the rate (2.5 pellets/day, each pellet's prey count? Wait, maybe the "Number found" for Rat is 1 (the line), so number eaten per day is 2.5, so per week 2.5×7=17.5, per year 2.5×365≈912.5. But the chart has 90 for Rat's per year (maybe a mistake, but following the given 2.5 per day).

Step3: Fill other rows (example: Shrew)

Suppose "Number found" for Shrew is, say, let's see the length is 8 cm. If we assume the same pellet rate (2.5 per day), but maybe the "Number found" is the count in pellets. Wait, the problem says "Fill in the chart as appropriate. You will not have data for every single species of prey. Remember, owls spit out 2.5 pellets/day on average." So each pellet has prey remains. So for each prey, "Number found" is the count in pellets, then "Number eaten per day" = (Number found) × (pellets per day? No, wait: owls spit 2.5 pellets/day, so total prey in pellets per day is sum of all prey in pellets. But maybe "Number found" is the number of that prey in all pellets, then "Number eaten per day" = (Number found) / (number of days to collect pellets)? Wait, maybe the chart's "Number found" is the total found in all pellets (over some days), then "Number eaten per day" = (Number found) / (days of collection) × (pellets per day? No, the key is using the 2.5 pellets/day. Let's take Rat: Number found is 1 (the line), so per day 2.5, so per week 17.5, per year ~912.5 (but chart has 90, maybe 36 weeks? 2.5×36=90). So the method is: for each prey, if "Number found" is \( n \), and if we assume the pellets were collected over \( d \) days, then per day = \( n / d \), but since the rate is 2.5 pellets/day, maybe "Number eaten per day" is 2.5 times the proportion? Wait, maybe the chart's "Number eaten per day" for Rat is 2.5 (given), so we use that to find week (2.5×7=17.5) and year (2.5×365≈912.5, but chart has 90, maybe a simplification).

Answer:

The chart filling uses the rate of 2.5 pellets per day. For a prey with "Number found" \( n \), "Number eaten per day" = \( n \times (2.5 / \text{total pellets analyzed}) \), but in the given Rat row, per day is 2.5, so per week \( 2.5 \times 7 = 17.5 \), per year \( 2.5 \times 365 \approx 912.5 \) (or 90 as in the chart, maybe a typo). Other rows follow the same multiplication by days in the period (7 for week, 365 for year) from the per - day rate.