Question

In: Statistics and Probability

When 415 college students are randomly selected and surveyed, it is found that 328 made online purchases during the last month.

When 415 college students are randomly selected and surveyed, it is found that 328 made online purchases during the last month. What sample size will produce a margin of error of 6% with 95% confidence level?

Solutions

Expert Solution

Number of Items of Interest,   x =   328
Sample Size,   n =    415
      
Sample Proportion ,    p̂ = x/n =    0.7904

--------------------------

sample proportion ,   p̂ =    0.7904
sampling error ,    E =   0.06                          
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   /   0.06   ) ² *   0.79   * ( 1 -   0.79   ) =    176.8
                                  
                                  
so,Sample Size required=       177         

   


Related Solutions

When 328 college students are randomly selected and surveyed, it is found that 122 own a...
When 328 college students are randomly selected and surveyed, it is found that 122 own a car. Find a 99% confidence interval for the true proportion of all college students who own a car. A) 0.328 < p < 0.416 B) 0.320 < p < 0.424 C) 0.310 < p < 0.434 D) 0.303 < p < 0.441
When 355 college students are randomly selected and surveyed, it is found that 129 own a...
When 355 college students are randomly selected and surveyed, it is found that 129 own a car. Construct a 96% confidence interval for the percentage of all college students who own a car. (3 decimal places)
1. When 258 college students are randomly selected and surveyed, it is found that 106 own...
1. When 258 college students are randomly selected and surveyed, it is found that 106 own a car. Find a 99% confidence interval for the true proportion of all college students who own a car. a.0.351 < p < 0.471 b.0.332 < p < 0.490 c.0.339 < p < 0.482 d.0.360 < p < 0.461
Suppose 250 randomly selected students in a college are surveyed to determine if they own a...
Suppose 250 randomly selected students in a college are surveyed to determine if they own a tablet. Of the 250 surveyed, 98 reported owning a tablet. a. explain whether normal model can be used in this situation b. find the standard error. c. Construct the 95% confidence interval and explain what it means in the context of the problem d. based on the college database, the proportion of students that owns a tablet in this college is 36% What is...
At a local college, 65 female students were randomly selected and it was found that their...
At a local college, 65 female students were randomly selected and it was found that their mean monthly income was $609. Seventy-five male students were also randomly selected and their mean monthly income was found to be $651. Test the claim that male students have a higher monthly income than female students. Assume the population standard deviation for the females is $121.50 and for the males $131. Use α = 0.01
Students at a college randomly selected 217 student cars and found that they had ages with...
Students at a college randomly selected 217 student cars and found that they had ages with a mean of 7.89 years and a standard deviation of 3.67 years. They also randomly selected 152 faculty cars and found that they had ages with a mean of 5399 years and a standard deviation of 3.65 years. a) Using a 0.05 significance level, are student cars older than faculty cars? List: Define the parameters u1 and u2 Null and Alternative Hypothesis P-value Initial...
A survey of 196 randomly selected college students at a local university found that only 78%...
A survey of 196 randomly selected college students at a local university found that only 78% of them checked their college email on a regular basis. The standard deviation is 7.4. Construct the confidence interval for the population proportion with a 90% confidence level.
In a time-use study, 20 randomly selected college students were found to spend a mean of...
In a time-use study, 20 randomly selected college students were found to spend a mean of 1.4 hours on the internet each day. The standard deviation of the 20 scores was 1.3 hours. Construct a 90% confidence interval for the mean time spent on the internet by college students. Assume t* = 1.729 If you increased the sample size for the problem above, what would happen to your confidence interval, assuming the sample mean and standard deviation remain unchanged?
a sample of 193 randomly selected students , found that the proportion of students planning to...
a sample of 193 randomly selected students , found that the proportion of students planning to travel home for thanksgiving is 0.71
A store owner surveyed 25 randomly selected customers and found the ages shown​ (in years). The...
A store owner surveyed 25 randomly selected customers and found the ages shown​ (in years). The mean is 33.24 and the standard deviation is 10.87. The owner wants to know if the mean age of all customers isis 29 years old. Use the given information to complete parts a through f.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT