Answer:
1 just 1 i need 20 characters but ok
4b is equivalent to b+b+b+b
Not sure about this but, is it a line?

Here, “p” is a numerator and “q” is a denominator. The examples of rational numbers are 6/5, 10/7, and so on. The rational number is represented using the letter “Q”. Like real numbers, the arithmetic operations, such as addition, subtraction, multiplication, and division are applicable to the rational numbers.
Using the Empirical Rule, it is found that the lifespans, in months, are given by:
1. 24 and 32.
2. 20 and 36.
3. 16 and 40.
<h3>What is the Empirical Rule?</h3>
It states that, for a normally distributed random variable:
- Approximately 68% of the measures are within 1 standard deviation of the mean.
- Approximately 95% of the measures are within 2 standard deviations of the mean.
- Approximately 99.7% of the measures are within 3 standard deviations of the mean.
Hence, considering the mean of 28 months and the standard deviation of 4 months, the life spans are given by:
1. 24 and 32.
2. 20 and 36.
3. 16 and 40.
More can be learned about the Empirical Rule at brainly.com/question/24537145