Mathematics
What are primary data and secondary data ? Which of the two are more reliable and why?
Answer
Primary Data : The data collected by the investigator himself with a definite plan in mind are known as primary data.
Secondary Data : The data collected by someone, other than the investigator are known as secondary data.
Primary data is more reliable than secondary data because primary data collected by the user himself.
Related Questions
Define statistics as a subject.
Fill in the blanks
(i) The difference between the maximum and minimum observations in a data is called the ………… of the data.
(ii) The number of observations in a class-interval is called the ………… of the interval.
(iii) The mid-point of a class-interval is called the ………… of the interval.
(iv) Lower-limit of the class-interval 24-30 is …………
(v) Upper limit of the class-interval 16-20 is …………
(vi) The class-mark of the class-interval is 20-30 is …………
(vii) The class-mark of the class-interval 9.5-19.5 is …………
Find the range of the data
(a) 5, 7, 16, 21, 8, 10
(b) 11, 13, 17, 14, 19, 14, 15, 18
The class marks of a frequency distribution are 28, 34, 40, 46, 52. Find the class-size and all the class intervals.