Answer:
second option is the right answer
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Answer:
= 25
Step-by-step explanation:
2 (-3)^2 - (4(-2) + 1)
2 (9) - (-8 + 1)
18 - (-7)
25
Answer:
Step-by-step explanation:
From the information given,
Number of personnel sampled, n = 85
Mean or average = 6.5
Standard deviation of the sample = 1.7
We want to determine the confidence interval for the mean number of years that personnel spent in a particular job before being promoted.
For a 95% confidence interval, the confidence level is 1.96. This is the z value and it is determined from the normal distribution table. We will apply the following formula to determine the confidence interval.
z×standard deviation/√n
= 1.96 × 6.5/√85
= 1.38
The confidence interval for the mean number of years spent before promotion is
The lower end of the interval is 6.5 - 1.38 = 5.12 years
The upper end is 6.5 + 1.38 = 7.88 years
Therefore, with 95% confidence interval, the mean number of years spent before being promoted is between 5.12 years and 7.88 years
Let, the total number of students in school that ride the bike to school be "x"
Now,
Using ratio and proportion, we get,
So, out of 800 students, 125 ride their bike to school.
The distance between them is 75 miles
after 1 hour the train will go 125 miles
125 miles.....1 hour
75 miles..........x hour
x=75/125=75/125*60=36 minutes
d is the answer
