Answer: observational study
Step-by-step explanation:

I divided by 100 and shifted the decimal point two places left.
Answer:
The anticipated number of tests required to identify 680 acceptable circuits is 907.
Step-by-step explanation:
For any circuit, there are two potential results: it either passes the test or it fails. The likelihood of passing is independent between circuits. Therefore, we apply the binomial probability distribution to address this scenario.
Binomial probability distribution
This distribution calculates the chance of obtaining exactly x successes across n trials, where x has only two possible outcomes.
To find the expected number of trials to achieve r successes with a probability p, the formula is given by:

Circuits from a specific factory pass a certain quality evaluation with a probability of 0.75.
Thus, to determine the expected number of tests needed for 680 acceptable circuits, let’s denote this as E where r = 680.



The expected number of tests necessary to find 680 acceptable circuits is 907.
Answer:
Yes, the cost
in dollars and the quantity of yogurt
are indeed proportional.
The relationship can be expressed as: 
Step-by-step explanation:
1. If
varies directly with
, it can be represented as:

Here,
represents the constant of proportionality.
2. We'll calculate the proportionality constant. Given that
and
, we have:

3. Thus, the equation becomes:

4. Now, we need to verify proportionality. Substituting
, which is the quantity of yogurt purchased by Jonah, we should arrive at $0.48:

5. They are indeed directly proportional.