Page 181 - Data Science class 11
P. 181

7.  There are basically two types of statistics—descriptive and inferential. Which of the following sentences are true about
                  descriptive statistics? (Hint: The answer is in the name descriptive statistics).
                  a.   Descriptive statistics enable you to make decisions about your data, for example, is one group mean
                     significantly different from the population mean?
                  b.  Descriptive statistics describe the data.

                  c.   Descriptive statistics enable you to draw inferences about your data, for example does one variable predict
                     another variable?

                  d.  All of these.
               8.  Sampling error can be reduced by:

                  a.  correcting a faulty sample frame
                  b.  increasing response rates

                  c.  increasing the sample size
                  d.  reducing incomplete surveys

            B.  Fill in the blanks.

               1.  ______________________ is the data that has already been collected in the past through primary sources and made readily
                  accessible for researchers so that they can use it for their own research.

               2.  Any group of data which includes all the data is called ______________________.
               3.  ______________________ type of survey is conducted in-person which takes into account a number of people.
               4.  Full form of NPS is ______________________.

               5.  ______________________ is the difference of population parameter and a sample statistic used to estimate it
            C.  State whether these statements are true or false.

               1.  Convenience sampling is a type of non-probability sampling.                             ____________
               2.  Information bias is an error-based bias in the way the survey respondents are chosen.   ____________
               3.  Systematic sampling selects a random starting point from the population, and then a sample is taken
                  a sample is taken from regular fixed intervals of the population depending on its size.   ____________

               4.  A transducer is any physical device that converts analog signal to digital signal.      ____________
               5.  XML has pre-defined tags.                                                               ____________


                 Standard Questions (Section B)

            A.  Short answer type questions:
               1.  What is XML parsing?

              Ans.  XML stands for eXtensible Markup Language. It refers to going through XML document to access data or to modify
                  data in one or other way. XML Parser provides way to access or modify data present in an XML document.
               2.  What is a sensor?

              Ans.  Sensor is a device that responds to a physical stimulus such as heat, light, sound, pressure, magnetism or a particular
                  motion and transmits a resulting impulse for automatically controlled actuators.
               3.  Write any two ways to avoid sampling bias.
              Ans.  i.  Use stratified random sampling

                       ii.  Avoid asking the wrong questions


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