A chemical company wishes to study difference in response times (in milliseconds) for number of different kinds of circuits employed in an automatic value shutoff mechanism. From past studies, the value of sigma is taken to be 2 milliseconds. The researcher has the list of over 100 Kinds of Circuits which are of interest to the company. The company desires to find out if there is important variation in the performance of 100 kinds of circuits. In order to control for variation within each and every type of circuit, she decides it is necessary to evaluate 5 circuits of each Type chosen for the study. How many different kinds of circuits should be selected for employ in the experiment in order to obtain an alpha=.01 test having power of at least 0.90 whenever standard deviation in the Types of circuits is greater than 2.1 milliseconds?