Forty men were elected from a city as a random sample and the male weights were weighed. Below are the weights to the nearest kilogram rounded:

74 87 80 71 77 67 80 83 78 84 75 79 73 79 81 77 89 68 74 93

86 65 82 87 78 92 76 78 73 81 75 73 85 77 73 76 80 83 78 69

M N = 40

Variable weight = 78.4

Mean Standard deviation = 6.456164

Determine the 95% confidence interval for the mean adult male body in Cochabamba,

1. assuming that the variance in weight has been measured in previous studies 6.324555² kg².
2. the sample is used to justify the estimated variance s² = 6.456².
3. What is the probability that from the city randomly selected 8 men, have the total weight of (the city's male resident) exceeds the town hall elevator the weight limit is 640 kg, assuming an average weight of 78.4 kg and a weight variance 6.324555² kg²