**821. for computing mean of a grouped data the major assumption we make is_________**

A. All values are discrete

B. No value occurs more than once

C. Each class contains exactly the same number of values**D. Every value in a class is equal to the midpoint**

**822. By the change of ______________ measures of dispersion are changed.**

A. origin**B. scale**

C. Algebra Sign

D. none of these

**823. When deviations are taken from __________ sum of absolute deviation of the value is least.****A. Median**

B. mode

C. Mean

D. weighted mean

**824. Which are the most commonly used measures of dispersion in quality control of manufactured items?**

A. Mean deviation

B. standard deviation

C. Quartile deviation**D. range**

**825. what is the sum of 10 numbers if there mean is 9**

A. 70

B. 80**C. 90**

D. 100

**826. For finding the average speed of a journey which is the appropriate average?**

A. Geometric mean**B. Harmonic mean**

C. Arithmetic mean

D. mode

**827. What is the geometric mean of two numbers x and y?**

A. xy

B. x – y

C. x + y**D. square root of xy**

**828. If all observations are increased by 10% and mean of 10 observations is 10. What is the increased observation?**

A. 15

B. 100

C. 30**D. 11**

**829. 2, 4, 8 and 64, find the geometric mean of these numbers.**

A. 64

B. 32

C. 16**D. 8**

**830. Mean, median and mode are always ______________ if the distribution is symmetrical.**

A. never equal**B. Always equal**

C. sometimes equal

D. none of these