An engineer wishes to determine the width of a particular electronic component. if she knows that the standard deviation is 1.6 mm, how many of these components should she consider to be 99% sure of knowing the mean will be within ±0.1±0.1 mm? a. 16 b. 4349 c. 1386 d. 42 e. 1699

n=1705

Step-by-step explanation:

The margin of error is the range of values below and above the sample statistic in a confidence interval.  

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".  

Assuming the X follows a normal distribution  

And the distribution for is:

We know that the margin of error for a confidence interval is given by:  

  (1)  

The next step would be find the value of , and  

Using the normal standard table, excel or a calculator we see that:  

If we solve for n from formula (1) we got:  

And we have everything to replace into the formula:  

And if we round up the answer we see that the value of n to ensure the margin of error required mm is n=1705.  

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: