Answer:
1. 1/3 plus 3/6
1/3 is the same as 2/6 so
2/6 plus 3/6 is 5/6
1=5/6
2. 1/4+2/8
2/8 is the same as 1/4 so
1/4 plus 1/4 is 2/4 which is the same as 1/2
2=1/2
Answer:
what
Step-by-step explanation:
Answer:
it is 3
Step-by-step explanation:
Answer:
a) The probability of obtaining a sample mean that is less than or equal to 1770 hours is P(M≤1770)=0.0013.
b) It is unusual, as there are only 13 chances in 10,000 (0.13%) of having this outcome.
Step-by-step explanation:
We have a population lifetime with mean of 1800 hours and standard deviation of 100 hours.
Samples of size n=100 are taken and tested.
We can calculate the probability of obtaining a sample mean that is less than or equal to 1770 hours using a z-score for the sample Mean M=1770 and then calculating its probability according to the standard normal distribution:
![z=\dfrac{X-\mu}{\sigma/\sqrt{n}}=\dfrac{1770-1800}{100/\sqrt{100}}=\dfrac{-30}{10}=-3\\\\\\P(X](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%2F%5Csqrt%7Bn%7D%7D%3D%5Cdfrac%7B1770-1800%7D%7B100%2F%5Csqrt%7B100%7D%7D%3D%5Cdfrac%7B-30%7D%7B10%7D%3D-3%5C%5C%5C%5C%5C%5CP%28X%3C1770%29%3DP%28z%3C-3%29%3D0.0013)