iSQI CTFL_Syll_4.0 Exam - Topic 5 Question 39 Discussion

Actual exam question for iSQI's CTFL_Syll_4.0 exam

Question #: 39
Topic #: 5

Following a risk-based testing approach you have designed 10 tests to cover a product risk with a high-risk level. You want to estimate, adopting the three-point test estimation technique, the test effort required to reduce the risk level to zero by executing those 10 tests. You made the following three initial estimates:

* most optimistic = 6 person hours

* most likely = 30 person hours

* most pessimistic = 54 person hours

Based only on the given information, which of the following answers about the three-point test estimation technique applied to this problem is true?

AThe final estimate is between 22 person hours and 38 person hours

BThe final estimate is exactly 30 person hours because the technique uses the initial most likely estimate as the final estimate

CThe final estimate is between 6 person hours and 54 person hours

DThe final estimate is exactly 30 person hours because the technique uses the arithmetic mean of the three initial estimates as the final estimate

Show Suggested Answer

Suggested Answer: A

The three-point test estimation technique is a method of estimating the test effort based on three initial estimates: the most optimistic, the most likely, and the most pessimistic. The technique uses a weighted average of these three estimates to calculate the final estimate, which is also known as the expected value. The formula for the expected value is:

Expected value = (most optimistic + 4 * most likely + most pessimistic) / 6

Using the given values, the expected value is:

Expected value = (6 + 4 * 30 + 54) / 6 Expected value = 30 person hours

However, the expected value is not the only factor to consider when estimating the test effort. The technique also calculates the standard deviation, which is a measure of the variability or uncertainty of the estimates. The formula for the standard deviation is:

Standard deviation = (most pessimistic - most optimistic) / 6

Using the given values, the standard deviation is:

Standard deviation = (54 - 6) / 6 Standard deviation = 8 person hours

The standard deviation can be used to determine a range of possible values for the test effort, based on a certain level of confidence. For example, using a 68% confidence level, the range is:

Expected value standard deviation

Using the calculated values, the range is:

30 8 person hours

Therefore, the final estimate is between 22 person hours and 38 person hours, which is option A.

by Fallon at Jul 05, 2025, 05:37 AM

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Sherill

2 months ago

The range should be wider than just 6 to 54 hours.

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Samuel

3 months ago

Definitely not just the most likely estimate!

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Rashida

3 months ago

Wait, how can we be sure it’s between 22 and 38 hours? Sounds off.

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Ezekiel

3 months ago

The final estimate is calculated using the three-point technique, not just the most likely.

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Pearline

3 months ago

I think the final estimate should be around 30 hours, but it’s not exact.

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Ivan

3 months ago

If I remember correctly, we usually calculate the final estimate using the average of the three values, so it shouldn't be exactly 30 hours.

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Vonda

4 months ago

I feel like the most likely estimate is important, but I don't think it means the final estimate is just 30 hours.

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Cecilia

4 months ago

I think the final estimate should be between the optimistic and pessimistic values, but I can't recall the exact formula we used in practice.

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Val

4 months ago

I remember the three-point estimation technique involves calculating a weighted average, but I'm not sure how to apply it here.

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Louisa

4 months ago

Alright, I've got this. The three-point estimation formula is (Optimistic + 4 x Most Likely + Pessimistic) / 6. Plugging in the values, that gives us a final estimate between 22 and 38 person hours. The answer is A.

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Dick

4 months ago

Wait, I thought the three-point technique used a formula to calculate the final estimate, not just the average. I'm a bit confused on the details, but I think the answer is A.

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Queenie

5 months ago

I remember learning about the three-point estimation technique in class. I believe the final estimate is calculated by taking the average of the three initial estimates, which would make the answer D.

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Josphine

5 months ago

Okay, let's see. The question gives us the most optimistic, most likely, and most pessimistic estimates. I think the final answer has to be somewhere between those values, but I'm not sure exactly how to calculate it.

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Raul

5 months ago

Hmm, this seems like a tricky one. I'll need to think through the three-point estimation technique carefully to figure out the right answer.

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Delmy

7 months ago

I see your point, but I still think it's between 22 person hours and 38 person hours.

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Vilma

7 months ago

I'm not sure, but I think the final estimate is between 6 person hours and 54 person hours.

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Elsa

7 months ago

I bet the test designers are just trying to keep us on our toes. Probably the right answer is something completely unexpected, like 42 person hours. That's the answer to life, the universe, and everything, after all!

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Dallas

5 months ago

C) The final estimate is between 6 person hours and 54 person hours

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Kenneth

6 months ago

A) The final estimate is between 22 person hours and 38 person hours

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Otis

7 months ago

Option C is the only one that includes the full range of the initial estimates. That's gotta be the right answer, right? Unless the test designers are trying to trick us...

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