Please show work for problems 10 - 12. Answer is provided, can not use excel.

Question 10 0 out of 0.6 points The average spending at Neco's salad bar is $9.60 with a standard deviation of $3.26. 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 cutoffs which define the middle 85% of the customers? Selected Answer: 0 9.8462 Correct Answer: 7. 9.39 i 0.01 Question 11 0 out of 0.6 points The average spending at Neco's salad bar is $9.03 with a standard deviation of $3.26. 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 cutoffs which define the middle 90% of the customers if the sample contains 41 customers? Selected Answer: 0 10.7254 Correct Answer: 7. 10.980 1 0.1% Question 12 0 out of 0.6 points The average spending at Neco's salad bar is $9.84 with a standard deviation of $3.49. 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 cutoffs which define the middle 80% of the customers? Selected Answer: 0 8.9448 Correct Answer: _. 8.93 i 0.01