You can upgrade lighting at your factory to led bulbs that costs $6.95 each and last an average of 5 years. it costs $3.00 in labor to change a bulb. over a 10-year period, about how much will it cost per year to install led bulbs in 100 lamps and change the bulbs when they burn out?

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables