Given that half of the personal music players sold by a particular brand have a flaw. If the player has the flaw, it dies in the first six months. If it does not have this flaw, then only 20% fail in the first six months.
Let A be the event that it fails in I 6 months
B1 = it has a flaw
B2 = it does not have a flaw
B1 and B2 are mutually exclusive and exhaustive
the chances that it has this flaw
=The probability that it has the flaw is
Answer:
95% of the population spent between 16.8 hours to 26.2 hours on social media per month
Step-by-step explanation:
- subtracting 1 from sample size: 83-1= 82
- Note Mean=21.5 and standard deviation=2.5
- Subtracting confidence interval from 1 and dividing by 2: (1-0.95)/2=0.025
- At α=0.025 and dF=82, the t-distribution table gives 1.984
- Divide standard deviation by square root of sample size: 21.5/√83= 2.36
- Multiplying answer in step 4 by answer in step 5: 2.36×1.984= 4.68
- For lower end: 21.5-4.68= 16.82
- for upper end: 21.5+4.68=26.18
I think the answer is: 6 = -21
If mark and 8 of his friends went out the total of people is 9, so if you think about it 9x9=81 so the total cost of the bill was $81