Question

In: Statistics and Probability

An investigator takes a random sample of n people from a certain population to obtain the...

An investigator takes a random sample of n people from a certain population to obtain the proportion p (hitherto unknown to the researcher) of smokers. Calculate the sample size you should take to ensure that the proportion of smokers does not differ from the true p-value by more than 0.01 with a probability of at least 0.95 using:

b) Central limit theorem

Solutions

Expert Solution

ANSWER:

b)

sample proportion ,   p̂ =    0.5                          
sampling error ,    E =   0.01                          
Confidence Level ,   CL=   0.95                          
                                  
alpha =   1-CL =   0.05                          
Z value =    Zα/2 =    1.960   [excel formula =normsinv(α/2)]                      
                                  
Sample Size,n = (Z / E)² * p̂ * (1-p̂) = (   1.960   /   0.01   ) ² *   0.50   * ( 1 -   0.50   ) =    9603.6
                                  
                                  
so,Sample Size required=       9604      

Sample size for a is greater than b

NOTE:: I HOPE THIS ANSWER IS HELPFULL TO YOU......**PLEASE SUPPORT ME WITH YOUR RATING......

**PLEASE GIVE ME "LIKE".....ITS VERY IMPORTANT  FOR,ME......PLEASE SUPPORT ME .......THANK YOU


Related Solutions

An investigator takes a random sample of n people from a certain population to obtain the...
An investigator takes a random sample of n people from a certain population to obtain the proportion p (hitherto unknown to the researcher) of smokers. Calculate the sample size you should take to ensure that the proportion of smokers does not differ from the true p-value by more than 0.01 with a probability of at least 0.95 using: a) Chebyshev´s inequality b) Central limit theorem Compare both values of n obtained, what can you conclude about it?
Suppose an investigator takes a random sample of n = 50 birth weights from several teaching...
Suppose an investigator takes a random sample of n = 50 birth weights from several teaching hospitals located in an inner-city neighborhood. In her random sample, the sample mean x is 3,150 grams and the standard deviation is 250 grams. (a) Calculate a 95% confidence interval for the population mean birth weight in these hospitals. (b) ThetypicalweightofababyatbirthfortheUSpopulationis3,250grams.Theinvestigatorsus- pects that the birth weights of babies in these teaching hospitals is different than 3,250 grams, but she is not sure if it...
Birth weights. Suppose an investigator takes a random sample of n = 50 birth weights from...
Birth weights. Suppose an investigator takes a random sample of n = 50 birth weights from several teaching hospitals located in an inner-city neighborhood. In her random sample, the sample mean x is 3,150 grams and the standard deviation is 250 grams. (a) Calculate a 95% confidence interval for the population mean birth weight in these hospitals. (b) The typical weight of a baby at birth for the US population is 3,250 grams. The investigator suspects that the birth weights...
5. A random sample of size n = 36 is obtain from a population with µ=...
5. A random sample of size n = 36 is obtain from a population with µ= 60 and standard deviation 12 (a). Describe the sampling distribution . (b). What is P(76.5 << 85.5 )?
A random sample of size n = 36 is obtain from a population with µ= 80,...
A random sample of size n = 36 is obtain from a population with µ= 80, and standard deviation =18. (a). Describe the sampling distribution . (b). What is P(77 << 85 )?
A random sample of size n = 225 is taken from a population with a population...
A random sample of size n = 225 is taken from a population with a population proportion P = 0.55. [You may find it useful to reference the z table.] a. Calculate the expected value and the standard error for the sampling distribution of the sample proportion. (Round "expected value" to 2 decimal places and "standard error" to 4 decimal places.) b. What is the probability that the sample proportion is between 0.50 and 0.60? (Round “z” value to 2...
A simple random sample of n measurements from a population is a subset of the population...
A simple random sample of n measurements from a population is a subset of the population selected in a manner such that which of the following is/are true? (Select all that apply. )Every sample of size n from the population has a proportionally weighted chance of being selected. Every sample of size n from the population has an equal chance of being selected. Every member of the population has an equal chance of being included in the sample.The simplest method...
A random sample of size n = 130 is taken from a population with a population...
A random sample of size n = 130 is taken from a population with a population proportion p = 0.58. (You may find it useful to reference the z table.) a. Calculate the expected value and the standard error for the sampling distribution of the sample proportion. (Round "expected value" to 2 decimal places and "standard error" to 4 decimal places.) b. What is the probability that the sample proportion is between 0.50 and 0.70? (Round “z” value to 2...
2. A simple random sample of 14 people from a certain population gives body mass indices...
2. A simple random sample of 14 people from a certain population gives body mass indices as shown in the Table below. Can we conclude that the mean BMI for this population is not 35? Subject BMI 23, 25, 21, 37, 39, 21, 23, 24, 32, 57, 23, 26, 31, 45
A random sample of size n is taken from a normally distributed population with a population...
A random sample of size n is taken from a normally distributed population with a population standard deviation (σ ) of 11.6. The sample mean (x) is 44.6. Construct a 99% confidence interval about µ with a sample size of 26.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT