Statistics & Prabability Basics | Fresco Play

Question 1: What is the numerical measure of average variability of a data set around the mean

Answer: Standard deviation

Question 2: Which type of statistics helps us understand how the data looks like without giving much information on analysis of the data?

Answer: Descriptive statistics

Question 3: Which of the following is an arithmetic mid-value?

Answer: Mean

Question 4: If a class consists of 20 males and 8 females, what is the probability of drawing 4 females without replacement?

Answer: P = (8/28)(7/27)(6/26)*(5/25)

Question 5: Your team has 10 members and you need 3 of them for an app development. How many possible combinations are there?

Answer: 120

Question 6: How many different ways can four team members from the group of fifteen be lined up for a photograph.

Answer: 1365

Question 7: Identify the variables that are continuous or discrete

Answer: Time & Weight are continuous. Color & Country are discrete

Question 8: When the Standard Deviation in a Normal Distribution is higher, which of the following is true?

Answer: The peak of the distribution is lower

Question 9: What are the characteristics of normal distribution

Answer: The mean lies at the center of the distribution

Question 10: There may be times when data is supposed to fit a normal distribution, but does not. Which of the following could be reasons for this?

Answer: Outliers and Small Sample Size

Question 11: In which of these examples, binomial distribution can be used?

Answer: Probability of getting a certain number of questions correct in an exam

Question 12: Which of the following characteristics correspond to a Binomial Distribution?

Answer: All the options

Question 13: Which of the following conditions are satisfied by Poisson random variable?

Answer: Probability that an event occurs in a given length of time does not change over time

Question 14: Which of the following conditions are satisfied by Poisson random variable?

Answer: Probability that an event occurs in a given length of time changes over time

Question 15: Which of the following can be modelled using Poisson distribution

Answer: Number of accidents that occur on a particular highway in a given month

Question 16: Any statement whose validity is tested on the basis of a sample is called:

Answer: Statistical hypothesis

Question 17: If a finding is statistically significant one must also interpret the data, calculate an effect size indicator, and make an assessment of practical significance

Answer: True

Question 18: The probability of rejecting the null hypothesis when it is true is called:

Answer: Level of significance

Question 19: After a clinical trial, it is concluded that both drugs A and B are equally effective. What type of a hypothesis is this?

Answer: Null hypothesis

Question 20: The significance level is the risk of:

Answer: Rejecting H0 when H0 is correct

Question 21: If you reject H0 but H0 is true, what type of error has occurred?

Answer: Type I

Question 22: Assuming innocence until proven guilty, a Type I error occurs when an innocent person is found guilty

Answer: True

Question 23: Which variable represents the actual Type I error?

Answer: P- value

Question 24: A Type I error is also known as a ______.

Answer: False positive

Question 25: A passing student is failed by an examiner, it is an example of:

Answer: Type-II error

Question 26: The shape of the t-distribution depends upon the:

Answer: Degrees of freedom

Question 27: Which of the following is not the purpose of student's t-distributions?

Answer: When modelling the actual number of failures in a trial

Question 28: Which of the following is not the purpose of using chi-square distributions?

Answer: To test how closely data follows a non-normal distribution

Question 29: What of the following is not a characteristic of F-distribution curve?

Answer: The curve is left skewed

Question 30: The ANOVA is a statistical test that is used to compare how many group means?

Answer: Two or more

Question 31: A post hoc test is:

Answer: A follow-up test to the ANOVA when there are three or more groups

Question 32: A statistical test used to compare 2 or more group means is known as:

Answer: One-way analysis of variance

Question 33: A statistician calculates a 95% confidence interval for Mean when Standard Deviation is known. The confidence interval is Rs.18000 to Rs.22000, the amount of the sample mean is:

Answer: 20000

Question 34: The p-value in statistical significance testing should be used to assess how strong a relationship is. For example, if relationship A has a p=.04 and relationship B has a p=.03 then you can conclude that relationship B is stronger than relationship A.

Answer: False

Question 35: The use of the laws of probability to make inferences and draw statistical conclusions about populations based on sample data is referred to as

Answer: Inferential statistics

Question 36: In which examples could binomial distribution be used?

Answer: Modelling the number of failures in a trial

Question 37: A good way to get a small standard error is to use a ________.

Answer: Large sample

Question 38: Any hypothesis which is tested for the purpose of rejection under the assumption that it is true is called?

Answer: Null hypothesis

Question 39: Confidence interval become narrow by increasing the:

Answer: Sample size

Question 40: An advertising agency wants to test the hypothesis that the proportion of adults in a country who read a Sunday Magazine is 25 percent. The null hypothesis is that the proportion reading the Sunday Magazine is:

Answer: Equal to 25%

Question 41: The analysis of variance is a statistical test that is used to compare how many group means?

Answer: Two or more

Question 42: Identify which of the following steps would not be included in hypothesis testing.

Answer: Eliminate all outliers

Question 43: An essential component of the Central Limit Theorem is that

Answer: All the options

Question 44: A failing student is passed by an examiner, it is an example of:

Answer: Type-I error

Question 45: The dividing point between the region where the null hypothesis is rejected and the region where it is not rejected is said to be

Answer: Critical value

Question 46: A door alarm works in 72 out of 100 cases and surveillance camera works in 68 out of 100 cases. What is the probability of effective screening techniques keeping in mind that these two methods can be used together?

Answer: 0.89

Question 47: In a hospital, 10% of patients have liver disease and 5% are alcoholics. Among those diagnosed with liver disease, 7% are alcoholics. If the patient is an alcoholic, what is their chances of having liver disease?

Answer: 0.14

Question 48: A watch manufacturer has two factories (FA, FB) and 60% of their watches are made at FA. It is known that 10% of them are made at FA and 15% made at FB are defective. What is the probability that a selected defective watch was manufactured at FB?

Answer: 0.05

Question 49: Central limit theorem and central tendency are same things

Answer: False