Math homework please help!!

2. Suppose that people’s weights are normally distributed, with mean 175 pounds and a standard deviation of 6 pounds. Round to the nearest hundredth of a percent
a. What percent of the population would weigh between 165 and 170 pounds?
b. What percent of the population would you expect to weigh more than 182 pounds?
c. What percent of the population would you expect to weigh between 172 and 180 pounds?

d. What percent of the population would you expect to be heavier than 163 pounds?

3. The weight of a can made from a machine is normally distributed with a mean of 25 grams and a
standard deviation of 0.4 grams. What percentage of the cans from this machine would not meet the
minimum required weight of 24 grams? Round to the nearest hundredth of a percent

4. Suppose that for a certain exam given nationwide is normally distributed with a mean of 80 and a
standard deviation of 3? Round to the nearest hundredth of a percent
a. What percent of the population would score higher than an 82?
b. What percent of the population would score between 78 and 85?
c. What percent of the population would score between 74 and 78?
d. What percent of the population would score above a 76?

You can play around with lots of Z table stuff at

http://davidmlane.com/hyperstat/z_table.html

have fun

i don't understand what information to put in and how to find the percent

To solve these types of problems, you would typically use the standard normal distribution table or a calculator that has a built-in normal distribution function. The table provides the areas to the left of the standard normal distribution curve, which can be converted to percentages. The calculator can directly calculate the probabilities without needing to convert to percentages.

Let's go through each question and explain how to solve them using the standard normal distribution table:

2a. To find the percentage of the population that would weigh between 165 and 170 pounds, you first need to convert these values to a standard deviation score (Z-score). To do this, subtract the mean (175) from each weight value and divide by the standard deviation (6):

Z1 = (165 - 175) / 6
Z2 = (170 - 175) / 6

Once you have the Z-scores, you can use the standard normal distribution table to find the probability associated with each Z-score. Look up the values in the table and subtract the smaller probability from the larger probability. Multiply the result by 100 to convert it to a percentage.

2b. For the percentage of the population that would weigh more than 182 pounds, you need to find the probability of the weight being less than 182 and subtract it from 1. Convert 182 to a Z-score using the same formula as above. Look up the probability in the table and subtract it from 1, then multiply the result by 100.

2c. To find the percentage of the population that would weigh between 172 and 180 pounds, you need to convert those weights to Z-scores and use the same process as described in 2a.

2d. For the percentage of the population that would be heavier than 163 pounds, you need to find the probability of the weight being greater than 163. Convert 163 to a Z-score and find the probability in the table, then multiply the result by 100.

3. For this question, you would use the same process as in question 2. Convert the minimum required weight of 24 grams to a Z-score and find the probability in the normal distribution table. Subtract that probability from 1 and multiply by 100 to get the percentage of cans that would not meet the minimum weight.

4a. To find the percentage of the population that would score higher than 82 on the exam, convert 82 to a Z-score and find the probability in the table. Subtract that probability from 1 and multiply by 100.

4b. To find the percentage of the population that would score between 78 and 85, convert those scores to Z-scores and find the probabilities associated with each Z-score. Subtract the smaller probability from the larger probability and multiply by 100.

4c. To find the percentage of the population that would score between 74 and 78, follow the same steps as in 4b.

4d. For the percentage of the population that would score above 76, convert 76 to a Z-score and find the probability in the table. Subtract that probability from 1 and multiply by 100.

Keep in mind that the standard normal distribution table provides probabilities for values to the left of the mean. To find probabilities for values to the right of the mean, you will need to subtract the probability from 1.