2, 10^{2} and 0^{2}); the sum of these squares is 200. If Luria and Delbrück determined that there were 0, 17, 58, 23, and 47 phage-resistant bacterial colonies in five different cultures, what would be the sum of the squares of the differences between these colony numbers and the mean number of bacterial colonies?
]]>n-1, where *n *represents the total number of data points. The resulting quotient is actually the variance for the data set being studied. For the height example, this step would be represented as 200/2 (as *n*=3, since the heights of 3 individuals were measured) or 100. Thus, the variance for this height data set is 100. What is the estimate of the variance for the phage-resistant colony data set discussed in Questions 1 and 2 (i.e., the 0, 17, 58, 23 and 47 phage-resistant colonies)?
]]>equal to the mean number of phage-resistant colonies (not higher than), mutations are likely induced by environmental factors.
]]>0 = e^{-m}, you have to “pull down” m from the exponent. To do this, researchers use a function called the natural logarithm (ln). For example, if you had the equation 0.23 = e^{-m}, the solution to this equation would be m = -ln (0.23). (The negative comes from the –m term in the exponent.) Almost all calculators have a ln function, and typing –ln(0.23) into a calculator would give you 1.5 (rounding to the nearest decimal place). In Question 7, you determined that Luria and Delbrück calculated a p_{0 }value of 0.33 for one of their experiments. Thus, for this experiment 0.33 = e^{-m}. What is the value of m (rounding to the nearest decimal place) in this equation? In other words, how many phage-resistance mutations occurred in this bacterial population during its culture?
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