Question

Here is a frequency distribution table (FDT) for a small data set:

data value	frequency
46	26
47	28
48	25
49	19
50	16

Find the following measures of central tendency.

mean (¯xx¯) =  (Please show your answer to one decimal place.)

median =  (Please enter an exact answer.)

mode =  (Please enter an exact answer.)

This data is from a sample. Calculate the mean, standard deviation, and variance.

x	25.4	22.9	20.5	19.9	37	37.6	40.6	21.9	23.9

Please show the following answers to 2 decimal places.

Sample Mean =

Sample Standard Deviation =

Sample Variance =

Ooops - now you discover that the data was actually from a population! So now you must give the population standard deviation.

Population Standard Deviation =

In a psychology class, 28 students have a mean score of 95.7 on a test. Then 25 more students take the test and their mean score is 66.

What is the mean score of all of these students together? Round to one decimal place.

mean of the scores of all the students =

Answer 1

data(x)	f requency(f)	Cumulative freq.	x.f
46	26	26	1196
47	28	54	1316
48	25	79	1200
49	19	98	931
50	16	114	800
Total	114	---	5443

So, mean = 5443/114=47.74

N/2= 114/2= 57 , SO median is the value containing the cumulative freq of 57 , which is 48

Mode is the value with highest frequency , which is 28,

So, mode = 47

• sample mean = 27.74 sample variance = 67.50 sample sd = 8.22

here n = 9

So, population sd = 7.31

• Grand mean =