Question

Manufacturing and Product Development A A typical washing machine has several different cycles, including soak, wash, and rinse. The energy consumption of a washing machine is linked to the length of each cycle. A random sample of 21 washing machines was obtained, and the length (in minutes) of each wash cycle was recorded. The summary statistics are x 37.8 and cycle times is normal. a. Find a 90% confidence interval for the true mean wash cycle time. Write a Solution Trail for this problem

Answer 1

Answer:

Explained

Step-by-step explanation:

here std error =std deviation/(n)^1/2 =1.2875

for 90% CI; at 21 degree of freedom =1.7247

hence confidence interval =mean +/- t*std error =35.579 ; 40.021

b) this interval gives 90% probability to contain true mean of population of wash cycle time

c)that interval would be wider as value of t will be greater for larger interval