Final answer:
Chebyshev's theorem guarantees that at least 95% of the Toyotas manufactured in the 1990s will have lifetimes between approximately 16.4 years and 28.8 years.
Step-by-step explanation:
According to Chebyshev's theorem, we can guarantee that at least 75% of the data lies within k standard deviations from the mean, where k is greater than 1. Therefore, to find the two lifetimes between which at least 95% of the Toyotas will be found, we need to determine the value of k. Since we want at least 95% of the data to be included, we subtract this value from 100% to get 5%. We divide this by 2 to get 2.5%. The corresponding k value that includes at least 97.5% of the data is 2. Therefore, we can say that between approximately 16.4 years and 28.8 years, we will find at least 95% of the Toyotas manufactured in the 1990s.