Accrotime is a manufacturer of quartz crystal watches. Accrotime researchers have shown that the watches have an average life of 26 months before certain electronic components deteriorate, causing the watch to become unreliable. The standard deviation of watch lifetimes is 4 months, and the distribution of lifetimes is normal. A button hyperlink to the SALT program that reads: Use SALT. (a) If Accrotime guarantees a full refund on any defective watch for 2 years after purchase, what percentage of total production will the company expect to replace? (Round your answer to two decimal places.) Incorrect: Your answer is incorrect. % (b) If Accrotime does not want to make refunds on more than 6% of the watches it makes, how long should the guarantee period be (to the nearest month)? months

a

b

Step-by-step explanation:

From the question we are told that

 The mean is  

 The standard deviation is  

 Generally 2 year is  equal to  24 months

Generally the percentage of total production will the company expect to replace is mathematically represented as

Generally  

Generally from the z-table  

So

Converting to percentage

=>      

Generally the duration that should be the guarantee period if  Accrotime does not want to make refunds on more than 6% is mathematically evaluated as

=>

From the normal distribution table the z-score for  0.06 at the lower tail  is

So

=>  

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.

51840000 cm 2

step-by-step explanation: