Question

graphing gestation times
(go with investigation 3, pages 236-237)
purpose: how do gestation times of different animals compare with each other? in this investigation, you will use a bar graph to compare different gestation times.

bar graph of gestation times
bar graph with y - axis \gestation time in months\, x - axis \animals\, and a data table: animal months cat 2 cow 10 dog 2 horse 8 goat 5 mare 11 rabbit 1 sow 4

questions and conclusions

1. which two gestation times are almost similar in length to the human gestation time?
2. what does each line in the scale on the left side of the graph represent?

explore further
assume that an animal can have an egg or eggs fertilized shortly after giving birth. calculate how many times each of the animals in your bar graph can give birth during one year (365 days). make a new bar graph that compares the information. explain how the length of gestation time affects the number of times an animal can give birth during one year.

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Explanation:

Question 1

First, identify human gestation time (typically around 9 months). Then check the table: Goat (5 months? Wait, no, maybe typo? Wait the table: Cat 2, Cow 10, Dog 2, Hare 3, Goat 5, Mare 11, Rabbit 1, Sow 4. Wait maybe human is ~9, so Cow (10) and Mare (11) are close? Or maybe I misread. Wait the table: Let's recheck. Animal: Cat (2), Cow (10), Dog (2), Hare (3), Goat (5), Mare (11), Rabbit (1), Sow (4). So human gestation is about 9 months. So Cow (10) and Mare (11) are almost similar (close to 9). Alternatively, maybe Goat? No. Wait maybe the problem's human gestation is considered as, say, 9, so Cow (10) and Mare (11) are near. Or maybe Hare? No. Wait the question is "almost similar to human gestation time". So Cow (10 months) and Mare (11 months) are close to human's ~9 months. Or maybe Goat? No. Wait maybe the table has a typo, but based on given data: Cow (10) and Mare (11) are the two closest to ~9.

The left scale is "Gestation Time in Months". The y - axis has lines, and looking at the data (e.g., Rabbit is 1, Cat/Dog 2, etc.), each line likely represents 1 month, as the gestation times are in whole months (1,2,3,4,5,10,11) and the scale is for months.

Step1: Determine gestation time (in days).

Rabbit: 1 month. Assume 1 month ≈ 30 days (simplified). So gestation time \( t = 30 \) days.

Step2: Calculate number of births in 365 days.

Number of births \( n=\frac{365}{t}\). For Rabbit: \( n = \frac{365}{30}\approx12.17 \), so ~12 times.
For Cat (2 months = 60 days): \( n=\frac{365}{60}\approx6.08 \), ~6 times.
For Dog (2 months = 60 days): ~6 times.
For Hare (3 months = 90 days): \( n=\frac{365}{90}\approx4.06 \), ~4 times.
For Goat (5 months = 150 days): \( n=\frac{365}{150}\approx2.43 \), ~2 times.
For Sow (4 months = 120 days): \( n=\frac{365}{120}\approx3.04 \), ~3 times.
For Cow (10 months = 300 days): \( n=\frac{365}{300}\approx1.22 \), ~1 time.
For Mare (11 months = 330 days): \( n=\frac{365}{330}\approx1.11 \), ~1 time.

Step3: Relationship: Shorter gestation time → more births per year (e.g., Rabbit with 1 - month gestation can give birth ~12 times, while Cow with 10 - month gestation can give birth ~1 time). So inverse relationship: as gestation time increases, number of births per year decreases.

Answer:

Cow (10 months) and Mare (11 months)

Question 2