In a study of cell phone usage and brain hemispheric dominance, an Internet survey was e-mailed to 6997 subjects randomly selected from an online group involved with ears. There were 12961296 surveys returned. Use a 0.01 significance level to test the claim that the return rate is less than 20%. Use the P-value method and use the normal distribution as an approximation to the binomial distribution.

Since the p value is very low we have enough evidence to reject the null hypothesis at the significance lvel given of 0.01 so then we can conclude that the return rate ofr this case is significantly lower than 20%

Step-by-step explanation:

Data given

n=6997 represent the random sample taken

X=1296 represent the returned surveys

estimated proportion of  returned surveys

is the value that we want to test

z would represent the statistic (variable of interest)

represent the p value (variable of interest)  

System of hypothesis

We need to conduct a hypothesis in order to test the claim that the true proportion of returned surveys is less than 0.2.:  

Null hypothesis:  

Alternative hypothesis:  

The statistic is given by:

(1)  

Calculate the statistic  

Since we have all the info required we can replace in formula (1) like this:  

Statistical decision  

The next step would be calculate the p value for this test.  

Since is a left tailed test the p value would be:  

Since the p value is very low we have enough evidence to reject the null hypothesis at the significance lvel given of 0.01 so then we can conclude that the return rate ofr this case is significantly lower than 20%

points are handed out whenever you post answers.

brainliest answers are handed out by the person asking the question, so whether your answer is picked depends entirely on whether the asker bothers to pick

if you're asking about your rank, it depends on having a certain number of points and a certain number of brainliest answers. for example, at the time of this writing, i have 44338 points out of 15000 needed for the next (nearly triple the requirement! ) but i only have 24 out of 50 required brainliest answers. this number decays, meaning after a certain amount of time (i think about a month), the total number of brainliest answers you've earned doesn't count toward this total. (i've been stuck at the same rank for a long

the lesson to learn here is that you shouldn't worry about points or rank. chances are, no matter how good an answer you may provide, your efforts will go mostly unnoticed unless you focus on the newest/most active questions that get posted.

32/80  

91/140

the last one 54 doesn't go into 45. 54/100 ?

step-by-step explanation: