I tried the whole thing I got some right and some wrong, and as well I meet a website but they have wrong answers kindly help am stuck ...

6. Find all critical points of f (2:,y) = 23;" + $2 62:3; and classify each critical point as a local maximum, local minimum or a saddle point by using partial derivatives. 6. A radio network determined that the time taken to play a baseball game is normally distributed with a mean of 160 minutes and a standard deviation of 1 5 minutes. How much time should the radio network program to be 86% sure that they can play the entire game without affecting programming? (3 marks) \f\f3. The mathematics test scores in Ramone's class are normally distribute. The mean is 75 and the standard deviation is 8. Ramone scored 92 on her test. Compare her score with the rest of the class. (2 marks)6. A radio network determined that the time taken to play a baseball game is normally distributed with a mean of 160 minutes and a standard deviation of 15 minutes. How much time should the radio network program to be 86% sure that they can play the entire game without affecting programming? (3 marks) 7. A 2010 poll determined that 65% of people agreed that wind power should be used over hydro power. The results of the survey are accurate within + 2.9 percentage points, 19 times out of 20. a) State the confidence level. (1 mark) b) Determine the confidence interval. (1 mark) c) The population of Nunavut was 33 220 in 2010. State the range of the number of Nunavut residents who agreed that wind power should be used over hydro power. (2 marks)4. A vinyl tile manufacturer produces floor tile that has an average thickness of 5 mm, with a standard deviation of 0.18 mm. For premium floor tiles, the flooring must have a thickness between 4.9mm and 5.2mm. What percent, to the nearest whole number, can be sold as premium tiles? (3 marks)17. A manufacturer of plasma televisions has determined that the televisions require servicing after a mean of 67 months, with a standard deviation of 7.2 months. What length of warranty should be offered, if the manufacturer wants to repair less than 1% of the televisions under the warranty