1. find the chi square value x 2 l corresponding to a sample size of 7 and a confidence level of 99%

2. find the critical value x 2 r corresponding to a sample size of 15 and a confidence level of 90%

1. χ² = 18.548

2. χ² = 23.685

Step-by-step explanation:

1. Confidence level is 99% (α = 0.01), but we're only interested in the left half, so α/2 = 0.005.  Degrees of freedom are 7−1 = 6.  Looking up in a chi square table, χ² = 18.548.

2. Confidence level is 90% (α = 0.10), but we're only interested in the right half, so α/2 = 0.05.  Degrees of freedom are 15−1 = 14.  Looking up in a chi square table, χ² = 23.685.