The power of -2 was mistook as 2.
Answer: 0.55567
Step-by-step explanation:
Given : A certain brand of refrigerator has a useful life that is normally distributed with mean 10 years and standard deviation 3 years. The useful lives of these refrigerators are independent.
i.e.
Let and are two randomly selected refrigerator's life whose sum will exceed third selected refrigerator .
So that,
Mean
Standard deviation =
Z-score :
Now , The probability that the total useful life of two(i..e n=2) randomly selected refrigerators will exceed 1.9 times the useful life of a third randomly selected refrigerator would be :-
Hence, the required probability is 0.55567.
C . [x: 2 ,3 ,4 ,5 ,7 ,9 ]
The answer is the option B. rotate 90 degrees counterclokwise and then rotate 270 degrees counterclockwise.
See that two consecutive rotations counterclockwise are equivalent to one single roration counterclockwise as long as the angles sum up the same.
Given that 90° + 270 ° = 360° means that the two rotaions are equivalent to one 360° rotation, and so the final figure will be the same as the original figure.
The ANWSER is B hope this helps