UPSC FEVER Certificate | Data Science | Free Quiz Certificate | Get Certificate Within 2 Minutes

            

UPSC FEVER Certificate | Data Science | Free Quiz Certificate | Get Certificate Within 2 Minutes

Question : Obtain a student directory with email addresses of all the university's students, and send the poll to every 50th name on the list. This sampling technique is called *

Answer : Systematic

 

Question : A midterm evaluation of a recitation instructor's teaching asked students to rate their instructor's preparation for class by choosing from one of the following: a) excellent; b) good; and, c) needs improvement. We may expect a summary of the instructor's teaching, based on the survey results, to be: 

Answer : biased towards a favorable summary

  

Question : Identify each of the following designs as being an observational study, a sample survey, or an experiment. Poll a sample of individuals with the following question: While watching TV, do you tend to snack: (a) less than usual; (b) more than usual; or (c) the same amount as usual? 

Answer : Sample survey

 

 

Question : Scales of Measurement is more precise as the differences can now be ranked. However, it does not indicate that the differences between two numbers are fixed or equal 

Answer : Ordinal

 

Question : The numerical measure that assesses the strength of a linear relationship is called 

Answer : Correlation Coefficient

 

Question : Scenario: Online Statistics Course A university was interested in examining the overall effectiveness of its online statistics course, along with the effectiveness of particular aspects of the course. First, the university wanted to see whether the online course was better than a standard course. Second, the university wanted to know whether students learned best using Excel, using Minitab, or using no statistical package at all. The university randomly selected a group of 30 students and administered one of the different variants of the course (i.e., traditional or online, coupled with one of the software options) to each student. The success of each variant was measured by the students' average improvement between a pre-test and a post-test. f we would like the treatments to be balanced in terms of the number of subjects, how many students should we assign to each treatment? 

Answer : 5

 

Question : For skewed right distributions and/or datasets with high outliers: 

Answer : Mean > Median

 

Question : Identify each of the following designs as being an observational study, a sample survey, or an experiment. Recruit participants for a study. Ask them to recall, for each hour of the previous day, whether they were watching TV, and what snacks they consumed each hour. Determine whether snack consumption was higher during the TV times. 

Answer : Observational study

 

Question : Students in a large statistics class were randomly divided into two groups. The first group took the midterm exam with soft music playing in the background, while the second group took the exam with no music playing. The scores of the two groups on the exam were compared. Which of the following is a reason this experiment is NOT blind? 

Answer : The students know whether or not music was playing while they were taking the exam

  

Question : Scales of Measurement in which the distance between pairs of consecutive numbers is assumed to be equal. However, variables do not have a meaningful zero point. 

Answer : Interval

 

Question : Measures the variability of a distribution by giving us the range covered by the MIDDLE 50% of the data. 

Answer : Inter quartile range

 

Question : A couple decides to have children until they have one boy and one girl, but they will not have more than three children. Choose the correct sample space for this random experiment. 

Answer : S = {GB, BG, BBG, GGB, BBB, GGG}

  

Question : Which statement is true? 

Answer : standard deviation is influenced by outliers, the IQR is not

 

Question : The technique that specifies the dependence of the response variable on the explanatory variable is called 

Answer : Regression

 

Question : Scenario: Online Statistics Course A university was interested in examining the overall effectiveness of its online statistics course, along with the effectiveness of particular aspects of the course. First, the university wanted to see whether the online course was better than a standard course. Second, the university wanted to know whether students learned best using Excel, using Minitab, or using no statistical package at all. The university randomly selected a group of 30 students and administered one of the different variants of the course (i.e., traditional or online, coupled with one of the software options) to each student. The success of each variant was measured by the students' average improvement between a pre-test and a post-test. Which of the following represents the explanatory variable(s)? 

Answer : Whether the course was online or traditional and the statistical software used.

 

Question : Identify the type of study design in the following scenario: Researchers classified pregnant women as being nondrinkers or light, moderate, or heavy drinkers; they examined the weights of their children at regular age intervals to see if alcohol during pregnancy results in poor growth. 

Answer : prospective observational study

 

Question : Which statement is true? 

Answer : 1, 2 and 3

 

Question : It is used as the basis for a rule of thumb for identifying outliers 

Answer : Inter quartile range

 

Question : Consider this survey question: "Every year, thousands of people, including children, are injured or killed because of the widespread availability of firearms in the United States. Do you agree that our country needs stricter gun control laws?" What is the response that surveyors hope to elicit? 

Answer : yes

 

Question : A variable that is not among the explanatory or response variables in a study, but could substantially affect your interpretation of the relationship among those variables. 

Answer : Lurking

 

 

Question : The most commonly occurring value in a distribution 

Answer : Mode

 

Question : Scenario: Online Statistics Course A university was interested in examining the overall effectiveness of its online statistics course, along with the effectiveness of particular aspects of the course. First, the university wanted to see whether the online course was better than a standard course. Second, the university wanted to know whether students learned best using Excel, using Minitab, or using no statistical package at all. The university randomly selected a group of 30 students and administered one of the different variants of the course (i.e., traditional or online, coupled with one of the software options) to each student. The success of each variant was measured by the students' average improvement between a pre-test and a post-test. Which of the following represents the response variable? 

Answer : The difference between the students' mean pre-test and post-test scores.

 

Question : In order to summarize the distribution of a categorical variable, we first create a table of the different values (categories) the variable takes, how many times each value occurs (count) and, more importantly, how often each value occurs (by converting the counts to percentages); this table is called a 

Answer : Frequency distribution

 

Question : What sampling technique is being used in this scenario? Voters are selected by choosing at random several of the city's zip codes and selecting all the voters from those selected zip codes. 

Answer : Cluster

 

Question : Probability is a measure of how likely an event is to occur. Choose the probability that best matches each of the following statements: This event will occur more often than not, but is not extremely likely:: 

Answer : 0.6

 

Question : Researchers wanted to study whether or not Botox injected under the arms can reduce sweating. Which of these is a matched pairs design? 

Answer : For each subject, one underarm is injected with Botox, and the other with salt water.

 

Question : A woman's pocket contains two quarters and two nickels. She randomly extracts one of the coins and, after looking at it, replaces it before picking a second coin. Let Q1 be the event that the first coin is a quarter and Q2 be the event that the second coin is a quarter. Are Q1 and Q2 independent events? 

Answer : yes

 

Question : Seeks to illuminate patterns in the data by summarizing the distributions of quantitative or categorical variables, or the relationships between variables 

Answer : Exploratory data analysis

 

Question : Which variables take category or label values and place an individual into one of several groups. Each observation can be placed in only one category, and the categories are mutually exclusive 

Answer : categorical

 

Question : A more practical approach in statistics would be to examine and collect data only from a subgroup of the population, which we call a 

Answer : sample

 

Question : The five-number summary of a distribution DOES NOT consist of 

Answer : Inter quartile range

 

Question : Scenario: Online Statistics Course A university was interested in examining the overall effectiveness of its online statistics course, along with the effectiveness of particular aspects of the course. First, the university wanted to see whether the online course was better than a standard course. Second, the university wanted to know whether students learned best using Excel, using Minitab, or using no statistical package at all. The university randomly selected a group of 30 students and administered one of the different variants of the course (i.e., traditional or online, coupled with one of the software options) to each student. The success of each variant was measured by the students' average improvement between a pre-test and a post-test. How many treatment groups are there in this study? 

Answer : 6

 

Question : Scenario: Online Statistics Course A university was interested in examining the overall effectiveness of its online statistics course, along with the effectiveness of particular aspects of the course. First, the university wanted to see whether the online course was better than a standard course. Second, the university wanted to know whether students learned best using Excel, using Minitab, or using no statistical package at all. The university randomly selected a group of 30 students and administered one of the different variants of the course (i.e., traditional or online, coupled with one of the software options) to each student. The success of each variant was measured by the students' average improvement between a pre-test and a post-test. Is this scenario a controlled experiment or an observational study? 

Answer : controlled experiment

 

Question : Identify each of the following designs as being an observational study, a sample survey, or an experiment. Recruit participants for a study. While they are presumably waiting to be interviewed, half of the individuals sit in a waiting room with snacks available and a TV on. The other half sit in a waiting room with snacks available and no TV, just magazines. Researchers determine whether people consume more snacks in the TV setting. 

Answer : Experiment

 

Question : Researchers wanted to study whether or not Botox injected under the arms can reduce sweating. Suppose each subject has one underarm injected with Botox, and the other with salt water. Which is the best way to make the assignment? 

Answer : Inject Botox under the left arm for some participants and the right arm for others, choosing the arm randomly. 

Question : Decide which type of study design was used for each of the following scenarios: A delivery company that owns a fleet of trucks performs a study to determine whether rotating tires at specific intervals has any effect on the number of miles a set of tires lasts. 

Answer : Experiment

 

Question : Identify the type of study design in the following scenario: Researchers injected some patients' underarms with Botox, and others' with salt water, in order to see if Botox (which was originally found to smooth wrinkles) would also reduce sweating. 

Answer : Experiment

 

Question : What sampling technique is being used in this scenario? Several pieces of fruit from each tree in an orchard are selected. 

Answer : Stratified

 

Question : It is the least precise measure of data as it only indicates differences. Scales of Measurement uses discrete categories to describe qualitative differences 

Answer : Nominal

 

Question : Identify each of the following designs as being an observational study, a sample survey, or an experiment. Recruit participants for a study. Give them journals to record hour by hour their activities the following day, including when they watch TV and when they consume snacks. Determine if snack consumption is higher during TV times. 

Answer : Observational study