STA-301 Assignment No. 4 Idea Solution Due Date June 27, 2012

[+ Abdul Rehman Aทઽα૨i]

STA-301 Assignment No. 4 Idea Solution Due Date June 27, 2012

 

 

 

[+ Abdul Rehman Aทઽα૨i]

fox bhai it is called confidence interval just read out the concept of confidence interval from handouts

jb bhi Z alpha by 2 ki value nikalty hain to alpha ko 2 py divide karty hain alpha question me given hy which is confidence interval 

....itna kuch smjha diya hay yar. 

BSC Punjab university doctor Sher ki book jo k Vu ne recommend ki hui hy also consult that

[Steve fox]

mainy sher muhammad CH. aur miraj din mirza dono he books kee hooee hain brother Q1(a) z alpha by 2= 0.02 and iski table value 2.054 hai jo round ho kar 2.06 ban rahi hai but aap jo keh rahay hain k0.96/2 yeh method nahi bcoz confidence interval 1-alpha k = hota hai , then phir alpha kee value 0.04 aati hai , then divide kar k 0.02 aati hai , then table main dekh kar 2.054 just checked it and also concerned with your teacher ok bro GOD BLESS YOU aur aap Q2 ka  (a) part tau theek kar do square tau aap ne liya he nahi ,, zara aap 1.645 ko 0.30 pe divide karo tau dekho kya 31 answer aata hai jo aap ne kiy howa hai?? just checked it ,, and thnxx for your cool behavior keep it up gud work ,, 

[+ Abdul Rehman Aทઽα૨i]

fox now check my solution again i have made some changes and now its full and final and accurate it was just 1-aplha that was written extra 

[aqsajabeen]

thanks dear................

[Syeda Kanwal Naqvi]

thanks Abdul Rehman 

yar amazing solution thanks again :)

[+ Abdul Rehman Aทઽα૨i]

Finding the critical value of alpha for two-tailed test

 

What is an alpha and confidence level?

As you know that a 95% confidence interval covers 95% of the normal curve (green area below) -- the probability of observing a value outside of this area is 5% or 0.05 (the decimal difference between 100% and 95%). This difference is commonly referred to as (alpha). (This area is other than the green colour)

 

How to find critical value of alpha for two-tailed test using z-table?

Lets follow the following steps

Let’s say you have an alpha level of 5%. (5% = 0.05 in decimal form).

Step 1: Subtract alpha from 1. (Since the total probability is ONE)

1 – 0.05 = 0.95 

Step 2 :Divide Step 1 by 2 (because we are looking for a two-tailed test)

0.95 / 2 = 0.475 

Step 3: Look at your z-table (given below) and locate the alpha level in the middle section/cells of the z-table.  

Step 4: In this example, you should have found the number .4750. Look to the far left or the row, you’ll see the number 1.9 and look to the top of the column, you’ll see .06. Add them together to get 1.96. That’s the critical value!

 

Note: The critical value is for two tail test and you are looking for both a left hand and a right hand tail, so don’t forget to add plus or minus! In our example you’d get ±1.96.

Note: Looking the table in this manner (step 3 & 4) is sometimes called the “inverse use” of area table)

 

Table – Areas for a Standard Normal Distribution

 

Z	0.00	0.01	0.02	0.03	0.04	0.05	0.06	0.07	0.08	0.09
0.0	0.0000	0.0040	0.0080	0.0120	0.0160	0.0199	0.0239	0.0279	0.0319	0.0359
0.1	0.0398	0.0438	0.0478	0.0517	0.0557	0.0596	0.0636	0.0675	0.0714	0.0753
0.2	0.0793	0.0832	0.0871	0.0910	0.0948	0.0987	0.1026	0.1064	0.1103	0.1141
0.3	0.1179	0.1217	0.1255	0.1293	0.1331	0.1368	0.1406	0.1443	0.1480	0.1517
0.4	0.1554	0.1591	0.1628	0.1664	0.1700	0.1736	0.1772	0.1808	0.1844	0.1879
0.5	0.1915	0.1950	0.1985	0.2019	0.2054	0.2088	0.2123	0.2157	0.2190	0.2224
0.6	0.2257	0.2291	0.2324	0.2357	0.2389	0.2422	0.2454	0.2486	0.2517	0.2549
0.7	0.2580	0.2611	0.2642	0.2673	0.2704	0.2734	0.2764	0.2794	0.2823	0.2852
0.8	0.2881	0.2910	0.2939	0.2967	0.2995	0.3023	0.3051	0.3078	0.3106	0.3133
0.9	0.3159	0.3186	0.3212	0.3238	0.3264	0.3289	0.3315	0.3340	0.3365	0.3389
1.0	0.3413	0.3438	0.3461	0.3485	0.3508	0.3531	0.3554	0.3577	0.3599	0.3621
1.1	0.3643	0.3665	0.3686	0.3708	0.3729	0.3749	0.3770	0.3790	0.3810	0.3830
1.2	0.3849	0.3869	0.3888	0.3907	0.3925	0.3944	0.3962	0.3980	0.3997	0.4015
1.3	0.4032	0.4049	0.4066	0.4082	0.4099	0.4115	0.4131	0.4147	0.4162	0.4177
1.4	0.4192	0.4207	0.4222	0.4236	0.4251	0.4265	0.4279	0.4292	0.4306	0.4319
1.5	0.4332	0.4345	0.4357	0.4370	0.4382	0.4394	0.4406	0.4418	0.4429	0.4441
1.6	0.4452	0.4463	0.4474	0.4484	0.4495	0.4505	0.4515	0.4525	0.4535	0.4545
1.7	0.4554	0.4564	0.4573	0.4582	0.4591	0.4599	0.4608	0.4616	0.4625	0.4633
1.8	0.4641	0.4649	0.4656	0.4664	0.4671	0.4678	0.4686	0.4693	0.4699	0.4706
1.9	0.4713	0.4719	0.4726	0.4732	0.4738	0.4744	0.4750	0.4756	0.4761	0.4767
2.0	0.4772	0.4778	0.4783	0.4788	0.4793	0.4798	0.4803	0.4808	0.4812	0.4817
2.1	0.4821	0.4826	0.4830	0.4834	0.4838	0.4842	0.4846	0.4850	0.4854	0.4857
2.2	0.4861	0.4864	0.4868	0.4871	0.4875	0.4878	0.4881	0.4884	0.4887	0.4890
2.3	0.4893	0.4896	0.4898	0.4901	0.4904	0.4906	0.4909	0.4911	0.4913	0.4916
2.4	0.4918	0.4920	0.4922	0.4925	0.4927	0.4929	0.4931	0.4932	0.4934	0.4936
2.5	0.4938	0.4940	0.4941	0.4943	0.4945	0.4946	0.4948	0.4949	0.4951	0.4952
2.6	0.4953	0.4955	0.4956	0.4957	0.4959	0.4960	0.4961	0.4962	0.4963	0.4964
2.7	0.4965	0.4966	0.4967	0.4968	0.4969	0.4970	0.4971	0.4972	0.4973	0.4974
2.8	0.4974	0.4975	0.4976	0.4977	0.4977	0.4978	0.4979	0.4979	0.4980	0.4981
2.9	0.4981	0.4982	0.4982	0.4983	0.4984	0.4984	0.4985	0.4985	0.4986	0.4986

Important Note: While looking for Z table in books or on internet, be sure to read the heading of the table and choose appropriate table.  For example, there are some other z-tables for finding the cumulative probabilities. So don’t get confuse.

 

More practice:

1. Repeat the above steps to find out the critical value for alpha 10%.
2. You can repeat this for any value of alpha J

[Steve fox]

yes this is called inverse use of area table, and bro aap ab aaye na 1-alpha pe , ab theak hai bro keep it up gud work bss aik point aur clear kar do ,

Q:1(b)  p-hat ka formula kya hai , because jo hum observed karte hain wo hamara 'X' hota hai and p-hat ka formula x/n hai ,, & given sample(n) hai 200 means p-hat=x/n ,, bro yeh point clear kar do ,, zara detail se batana ,, aur aap ne  hum direct he 30% ko p-hat kyun aur kis tarha liya wo bhi bataye brother... em waiting for your reply

[sparklytiger]

Thank you so much Abdul Rehman for explaining this, I have not been able to understand how to use the z table from the lectures and books, but you explained it perfectly!

[+-_-_*Ca$uAL$ mcs*_-_-]

solution plzzzzzzzzzzzzzzz?

[Steve fox]

 brother take it positive ok .. just clear my all points k main kahan galat hon ok brother

Now on Q1(b) aaap ne "P cap" kaise neekala ???? yeh aap bhi shayad jaante hain k aap ne direct he "P cap" ko 30% value de dee hai means 0.30 but aap jaante hain k yeh galt hai so poora answer galat aur Q1(a) bhi totally galat jab table value he theak nahi likhi ho tau???

[+ Abdul Rehman Aทઽα૨i]

fox bro P cap given hy read the question keenly 

[Steve fox]

" bhai jaan P cap given nahi hai actually Pcap ka formula hota hai x/n so x is 0.30 and n is 200 ?? am i right ?? nahi tau google pe just P hat likho aapko formula mil jaye ga