Betty has several of the standard six-sided dice that are common in many board games. If Betty rolls one of these dice, what is the probability that she rolls a three? use 3 decimal places.

A dog allergy test for people has a 98% accuracy rate. Only 1% of the population has an allergy to dogs (actually it is much smaller than that!). Use a group of 100,000 people who've taken this test and the information provided to complete a table and answer the following question:

If you tested negative, what is the probability you have a dog allergy?

A dog allergy test for people has a 90% accuracy rate. Only 1% of the population has an allergy to dogs (actually it is much smaller than that!). Assume a major pet food manufacturer purchases this test and administers it to 1,000 employees.


(Test is +) (-) (Total)
Has Allergy:
Not Allergy:
Total:

LOL this is why it is so hard to do this sort of test

more positives will be due to that 10% wrong accuracy problem than due to having allergy.

out of 1000 people, 10 have allergy
out of these 10 who have it
.9 * 10 = 9 test positive correctly
1 gets missed

out of the 990 who do not have allergy .10 *990 = 99 test positive incorrectly

get it?

did you get from such a simple first problem to the problem that messes up people who write papers on this sort of thing ?

To find the probability of rolling a three on a standard six-sided die, we need to determine the number of favorable outcomes (rolling a three) and the total number of possible outcomes.

In this case, we know that a standard six-sided die has six possible outcomes, which are the numbers 1, 2, 3, 4, 5, and 6.

Since we are interested in rolling a three, there is only one favorable outcome, which is rolling a three.

Therefore, to calculate the probability, we divide the number of favorable outcomes by the total number of possible outcomes:

Probability of rolling a three = (Number of favorable outcomes) / (Total number of possible outcomes)

Probability of rolling a three = 1 / 6 ≈ 0.167 (rounded to 3 decimal places)

Thus, the probability that Betty rolls a three on a standard six-sided die is approximately 0.167 or 16.7%.

1/6 = 0.167

A dog allergy test for people has a 90% accuracy rate. Only 1% of the population has an allergy to dogs (actually it is much smaller than that!). Assume a major pet food manufacturer purchases this test and administers it to 1,000 employees.


~~~~~~~~~~~(Test is +) (-) (Total)
Has Allergy:
Not Allergy:
Total: