The range rule of thumb roughly estimates the standard deviation of a data set as

a. s equals startfraction range over 4 endfraction .
b. s equals (mean )minus 2 times (standard deviation ).
c. s equals (mean )plus 2 times (standard deviation ).
d. s equals startfraction range over 2 endfraction .

Now, martin can reasonably guess that the standard deviation for the entire population of people at the mall during the time of the survey is $1.50. what is the 95% confidence interval about the sample mean? interpret what this means in the context of the situation where 95 people were surveyed and the sample mean is $8. use the information in this resource to construct the confidence interval.