Question

If the median of the dataset xi ,i=1,2,...,n, is 12, what is the median of the dataset 3xi +4, i=1,....,n?
e)The sample mean and sample variance of five data values are, respectively 13.6 and 25.8. If three of the data values are 7, 13 and 20, what are the other two data values? ________, ________.
f)The sample standard deviation of the dataset 2, a, 12, 18, and 30 is 10.8 (correct upto one decimal place), where a is an unknown quantity. Then, the value of the sample variance of the new dataset that is obtained by adding 5 to each number of the given dataset is __________.
g)Let the sample mean of a set of 20 data points be 30. If it is discovered that a data point having value 25 was incorrectly entered as 15, what should be the revised value of the sample mean?​​

Answer 1

Answer:

40

Explanation:

median = 12; n= 23

since n is odd

for 3x+4:

1st term= 3*1+4=7; last term=3*23+4=73

so median= (7+73)/2 =40

OR

Since median is 12th term from 1...n

Hence Median for 3xi+4 = 3*12+4=40