# What is the probability that it is defective?

Table of Contents

- 1 What is the probability that it is defective?
- 2 What is the probability that there will be at least one defective?
- 3 What is the probability of at least one event occurring?
- 4 What is the probability of choosing first two non defective bulbs followed by a defective bulb?
- 5 What is the probability of a machine getting out of adjustment?
- 6 Can We assume that the probability of 200 samples are independent?

## What is the probability that it is defective?

Probability of defect is the statistical chance that a product or process will not meet performance specifications or lie within the defined upper and lower specification limits. It is the ratio of expected defects to the total output.

**How do you find the probability of defective items?**

Let x be the number of defective items. The probability of an item being defective (p) is 3/12=1/4. So, the probability of non-defective items is (q)=3/4. Hence, the probability distribution of defective items is for x=1,2 and 3.

### What is the probability that there will be at least one defective?

Getting no defective items. 1 – (1/5) =4/5. The probability of getting at least one defective item when drawing three items from a batch of 6 items when 2 items are defective is 4/5 or 80\%.

**What is the probability that the chosen item is not defective?**

Therefore the probability of selecting a non-defective item is 0.99.

#### What is the probability of at least one event occurring?

To calculate the probability of an event occurring at least once, it will be the complement of the event never occurring. This means that the probability of the event never occurring and the probability of the event occurring at least once will equal one, or a 100\% chance.

**How do you find at least one probability?**

Starts here3:56Calculating the Probability for At Least One – YouTubeYouTube

## What is the probability of choosing first two non defective bulbs followed by a defective bulb?

If you chose a non-defective and a defective bulb you did so by either choosing a non-defective and then a defective or a defective and then a non-defective. Each possibility has probability 1/3 so the probability of choosing a non-defective and a defective bulb is 1/3 + 1/3 = 2/3.

**What is the probability that an item is not defective?**

Probability (p) that an item is defective is .015. Hence, the probability (q) that an item is not defective is 1 − .015 = .985 So, in a sample of n items, the probability that there is x defective items is C ( n, x) p x q n − x Here, n = 200, x=0.

### What is the probability of a machine getting out of adjustment?

If the items are independent then the probability is ( 1 – 0.015) 200 = 0.049. However, it is common for a machine to get out of adjustment so that when one item is defective, others are more likely to be defective as well.

**What is the probability that a lamp has a defect?**

In a large amount of electric lamps, 5\% are defective. A random sample of 8 lamps is taken for inspection. What is the probability that it has one or more defectives?

#### Can We assume that the probability of 200 samples are independent?

However, that computation assumes the probability of any of the 200 in the sample is independent from each other… and I think we can’t assume that, in the general case. When the number of items is very big, like more than 20000 or more than 200 000 that assumption would be a reasonable approximation, but in other cases it’s not.