need help please

1. The assembly time for a product is uniformly distributed between 6 and 10 minutes. What is the probability that on a given day, the product will take between 7.2 and 7.9 minutes?

2. The average spending at Neco's salad bar is $9.53 with a standard deviation of $3.24. The distribution follows Normal distribution. The management is interested in the middle 85% of the customers (spending wise) as it believes that they represent the customer base. What will be the difference between the upper and lower spending cut-offs which define the middle 85% of the customers?

3. The average spending at Neco's salad bar is $9.9 with a standard deviation of $2.68. The distribution follows t-distribution. The management is interested in the middle 90% of the customers (spending wise) as it believes that they represent their true customer base. What will be the difference between the upper and lower spending cut-offs which define the middle 90% of the customers if the sample contains 41 customers?

4. The average spending at Neco's salad bar is $9.7 with a standard deviation of $3.45. The distribution follows Normal distribution. The management is interested in the middle 80% of the customers (spending wise) as it believes that they represent the customer base. What will be the difference between the upper and lower spending cut-offs which define the middle 80% of the customers?

5. The baking time for a cake is uniformly distributed between 16 and 22 minutes. What is the probability that on a given day, the product will take more than 21.2 minutes?

6. The weights of the potatoes is your garden is normally distributed. If the middle 95.44% weigh between 4.82 and 9.21 ounces, then what is the standard deviation of the weights?

7. The weights of the tomatoes is normally distributed. If the middle 83% weigh between 2.24 ounces and 5.29 ounces, then what is the mean weight of the tomatos?

8. Z is a standard normal variable. Find the value of z in the following.

1.	The area between 0 and z is 0.4678.
2.	The area to the right of z is 0.1112.
3.	The area to the left of z is 0.8554
4.	The area between -z and z is 0.754.
5.	The area to the left of z is 0.0681.
6.	The area to the right of z is 0.9803.

10. There are 90 people in the restaurant. The probability of someone ordering a drink with the food is 60%. Use Normal approximation of Binomial Distribution to answer the following 6 questions.

1. What is the mean of the Normal distribution?

2. What is the standard deviation of the normal distribution?

3. What is the probability that exactly 50 people will order a drink?

4. What the probability that more than 50 people will order a drink?

5. What is the probability that less than 50 people will order a drink?

6. What is the probability that between 52 or more and 56 or less people will order a drink?