According to data from a metro station, 28% of trains are delayed. When compared to weather data, it was found that 73% of train delays and 35% of on-time rides were on days with precipitation. Given there is precipitation, what is the probability the train will be delayed?
Table of contents
- 1. Introduction to Statistics53m
- 2. Describing Data with Tables and Graphs2h 1m
- 3. Describing Data Numerically2h 8m
- 4. Probability2h 26m
- 5. Binomial Distribution & Discrete Random Variables3h 28m
- 6. Normal Distribution & Continuous Random Variables2h 21m
- 7. Sampling Distributions & Confidence Intervals: Mean3h 37m
- Sampling Distribution of the Sample Mean and Central Limit Theorem19m
- Distribution of Sample Mean - Excel23m
- Introduction to Confidence Intervals22m
- Confidence Intervals for Population Mean1h 26m
- Determining the Minimum Sample Size Required12m
- Finding Probabilities and T Critical Values - Excel28m
- Confidence Intervals for Population Means - Excel25m
- 8. Sampling Distributions & Confidence Intervals: Proportion1h 33m
- 9. Hypothesis Testing for One Sample3h 32m
- 10. Hypothesis Testing for Two Samples4h 49m
- Two Proportions1h 12m
- Two Proportions Hypothesis Test - Excel28m
- Two Means - Unknown, Unequal Variance1h 2m
- Two Means - Unknown Variances Hypothesis Test - Excel12m
- Two Means - Unknown, Equal Variance15m
- Two Means - Unknown, Equal Variances Hypothesis Test - Excel9m
- Two Means - Known Variance12m
- Two Means - Sigma Known Hypothesis Test - Excel21m
- Two Means - Matched Pairs (Dependent Samples)42m
- Matched Pairs Hypothesis Test - Excel12m
- 11. Correlation1h 24m
- 12. Regression1h 59m
- 13. Chi-Square Tests & Goodness of Fit2h 31m
- 14. ANOVA2h 1m
4. Probability
Bayes' Theorem
Struggling with Statistics for Business?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
A rare condition affects 1 out of every 100 people. The test for this condition has the following probabilities: If a person has the condition, the test is correct 95% of the time. If a person does not have the condition, the test gives a wrong result 10% of the time. If A is the event 'tested positive' and B is the event 'has condition,' find P(B'), P(AIB), and P(A|B').
A
P(B') = 0.99; P(A|B) = 0.95; P(A|B') = 0.10
B
P(B') = 0.99; P(A|B) = 0.95; P(A|B') = 0.01
C
P(B') = 0.95; P(A|B) = 0.99; P(A|B') = 0.01
D
P(B') = 0.95; P(A|B) = 0.99; P(A|B') = 0.10
Verified step by step guidance1
Step 1: Understand the problem and identify the key probabilities. The problem involves conditional probabilities and complements. The condition affects 1 out of 100 people, so the probability of having the condition, P(B), is 0.01. The complement, P(B'), is the probability of not having the condition, which is 1 - P(B).
Step 2: Calculate P(B'). Since P(B) = 0.01, the complement is P(B') = 1 - 0.01. This represents the probability that a person does not have the condition.
Step 3: Identify P(A|B). This is the probability that a person tests positive (event A) given that they have the condition (event B). The problem states that the test is correct 95% of the time for those with the condition, so P(A|B) = 0.95.
Step 4: Identify P(A|B'). This is the probability that a person tests positive (event A) given that they do not have the condition (event B'). The problem states that the test gives a wrong result 10% of the time for those without the condition, so P(A|B') = 0.10.
Step 5: Summarize the results. The probabilities are P(B') = 0.99, P(A|B) = 0.95, and P(A|B') = 0.10. These values can now be used for further analysis or decision-making.
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