Let X represent the number of pennies.
Let Y represent the number of nickels.
We know that X + 5Y = (Y + 5X) + 80.
4Y = 4X + 80
Y = X + 20
Hence, the difference between the number of pennies and the number of nickels is 20.
Answer:
1. A matched-pairs t-test is valid, despite the sample being a small representation of the population, because the sample is a simple random sample and has a distribution with a single peak.
Step-by-step explanation:
The matched-pairs test is valid, for the reasons given in choice 1. Here's why:
- We do have matched pairs, not a 2-sample t-test, because each two are paired by the house they live in. Husband and wife live together: it's safe to pair them. (This rules out option 5.)
- Check conditions: The sample is large enough (fulfilling the <u>sample size condition)</u>. The sample data is fairly normal, although we don't know the population data, and the sample size is over 40, so we consider it a fairly large sample (fulfilling the <u>nearly normal condition)</u>. We don't know about outliers, but we'll have to assume Ted doesn't have any, because they aren't mentioned.
Answer:
Given that a beetle has the pattern, 0.098 is the probability that it belongs to the rare subspecies
Step-by-step explanation:
Probability of having a pattern in rare subspecies ![= 0.98\\](https://tex.z-dn.net/?f=%3D%200.98%5C%5C)
Percentage of rare subspecies = 1 % = 0.01
Probability of a beetle with pattern belonging to rare subspecies is
![=0.01 * 0.98 \\= 0.098](https://tex.z-dn.net/?f=%3D0.01%20%2A%200.98%20%5C%5C%3D%200.098)
-11-1 over -2-4 which equals -12 over -6
Simplified to -2