1.) How do i obtain vitamin D blood levels on the entire US population of landscape gardeners. The population average level of vitamin D in US landscapers was found to be 53.67 ng/mL with a standard deviation of 5.167 ng/mL. Assuming the true distribution of blood vitamin D levels follows a Gaussian distribution, if you randomly select a landscaper in the US, what is the probability that his/her vitamin D level will be between 45.56 and 60.24 ng/mL?Please show steps as i need to check to see if my answer is correct.

2.) The population average level of vitamin D in US landscapers was found to be 54.25 ng/mL with a standard deviation of 5.211 ng/mL. Assuming the true distribution of blood vitamin D levels follows a normal distribution, if you randomly select a landscaper in the US, what is the likelihood that his/her vitamin D level will be 62.16 ng/mL or less? Please show steps as i need to check to see if my answer is correct.

3.) The population average level of vitamin D in US landscapers was found to be 32.87 ng/mL with a standard deviation of 4.529 ng/mL. Assuming the true distribution of blood vitamin D levels follows a Gaussian distribution, what is the lower value of the region for which approximately 68% of the data are located within the distribution? Please show steps as i need to check to see if my answer is correct.

4.) The population average level of vitamin D in US landscapers was found to be 43.94 ng/mL with a standard deviation of 4.63 ng/mL. Assuming the true distribution of blood vitamin D levels follows a Gaussian distribution, if you randomly select a landscaper in the US, what is the likelihood that his/her vitamin D level will be 33.77 ng/mL or less?Please show steps as i need to check to see if my answer is correct.