A research team has developed a face recognition device to match photos in a database. From laboratory tests, the recognition accuracy is 92% and trials are assumed to be independent.

(a) If the research team continues to run laboratory tests, what is the mean number of trials until failure?
(b) What is the probability that the first failure occurs on the tenth trial? Round your answer to four decimal places.
(c) To improve the recognition algorithm, a chief engineer decides to collect 6 failures. How many trials are expected to be needed? Round your answer to one decimal place

a) mean number of trails =1/p=1/(1-0.92)=12.5

b)

probability=(0.92)9*0.08=0.6624

c)

expected number of trails required =6/0.08=75

Step-by-step explanation:

arithmetic sequence

step-by-step explanation:

given that a sequence has terms as

19, 15, 11,

this is represented on a graph

the pattern indicates that the sequence is an arithmetic sequence with i term

a=19 and common difference d =-4

any general term

thus the sequence is reduced by 4 for each successive term starting from 1 and nth term is

24-5n.

first negative term would start after 5th term

5th term =24-25< 0

from 5th term onwards the sequence would be negative.

it is contrapositive

i could not see the question too well so check yourself again too . this is because i want you to get it correct.