Answer:
0.9641 = 96.41% probability that the life span of the monitor will be more than 15,579 hours.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean  and standard deviation
 and standard deviation  , the zscore of a measure X is given by:
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

Find the probability that the life span of the monitor will be more than 15,579 hours.
This is 1 subtracted by the pvalue of Z when X = 15579. So



 has a pvalue of 0.0359
 has a pvalue of 0.0359
1 - 0.0359 = 0.9641
0.9641 = 96.41% probability that the life span of the monitor will be more than 15,579 hours.
 
        
             
        
        
        
M<2 = 89
m<7 = m<2 = 89
m<3 = 180 - 89 = 91
m<8 = m<3 = 91
m<10 =23
m<11 = 62
m<9 = 180 - (62 + 91)
m<9 = 27
m<14 = 1/2 (63+18)
m<14 = 40.5
m<13 = 180 -40.5 = 139.5
m<12 = 180 - (57 + 63) = 60
m<17 = 180 - (60 + 40.5) = 79.5
m<27 = 90
m<25 = 63/2 = 31.5
m<24 = 57/2 = 28.5
m<26 = 90 - (31.5 + 28.5) = 30
m<19 = 180 - (30 + 79.5) = 70.5
m<18 = 180 - 70.5 = 108.5
m<15 = (60+23+63)/ 2 = 73
m<20 = 60/2 =30
m<21 = 90 - 30 = 60
m<22 = 180 -(70.5 + 60) = 49.5
m<23 = 180 -(31.5 + 108.5) = 40
62 + 23 + 63 + 57 = 205
60 + 18 = 78
m<16 = 1/2(205 - 78) = 63.5
m<4 = 1/2(62-13) = 24.5
m<5 = 180 - 24.5 = 155.5
m<6 = m<5 = 155.5
m<1 = 180 -(24.5 + 91) = 64.5
        
             
        
        
        
Step-by-step explanation:
x= 35+8
x= 43
y= 35+7
y= 42
 
        
             
        
        
        
160 is the first because 1 inches 20 but it says 2 inches so at 40+40+40+40
and the 2nd part is yes he is correct because he converted the inches into feet so i think he is also correct