Question

Using your calculator, find the range and standard deviation, round to two decimals places: The table below gives the number of hours spent watching TV last week by a sample of 24 children. Range-7에 Standard Deviation

Answer 1

Solution:

We are given following data set of 24 children which gives the number of hours spent watching TV in the last week.

68	89	35	52	44	89
76	32	85	63	29	61
89	51	88	43	69	71
28	41	50	30	99	19

We have to use calculator to find Range and Standard deviation.

In TI-83/84 plus calculator, we use following steps:

Step 1) Press STAT button

Step 2) Select EDIT and under EDIT select L1 column

If there are old numbers, then delete all those and enter new numbers given in above table one by one.

Step 3) Press STAT again

Step 4) Select CALC

Under CALC , select 1: 1-Var Stats

For List : L1 is already there, if not then Press 2ND and Number 1 button , then L1 will appear there.

for freqlist keep blank and move to Calculate and press Enter

This will give result from which we can get Sample Standard Deviation = Sx

Thus Sample Standard Deviation = Sx = 23.8178

Sx = 23.82 ( Rounded to 2 decimal places)

For range, we use Max and Min, scroll down and we get Min = 19 and Max = 99

Thus Range = Max - Min = 99 - 19

Range = 80

( Note: Please mention if you are using any other type of calculator)