Answer:
40
Step-by-step explanation:
120/3 equal to 40 words
Answer: 2.5 minutes
Step-by-step explanation: First convert feet to miles. There's 5280 feet in 1 mile, so 3300/5280=0.625 miles. Then find out how long in hours it takes to travel that far. It travels 15 miles an hour, so 0.625/15=0.0417 hours. Then convert hours to minutes by multiplying by 60. 0.0417*60=2.5 minutes.
Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the mean amount of time that teens spend online each week.
Number of sample, n = 41
Mean, u = 43.1 hours
Standard deviation, s = 5.91 hours
For a confidence level of 90%, the corresponding z value is 1.645. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean +/- z ×standard deviation/√n
It becomes
43.1 ± 1.645 × 5.91/√41
= 43.1 ± 1.645 × 0.923
= 43.1 ± 1.52
The lower end of the confidence interval is 43.1 - 1.52 =41.58
The upper end of the confidence interval is 43.1 + 1.52 =44.62
Therefore, with 90% confidence interval, the mean amount of time that teens spend online each week is between 41.58 and 44.62
Answer:
Step-by-step explanation:
It is a sphere with radius r = 5 cm
volume = (4/3)πr³
= (4/3)π(5³)
≅ 523.60 cm³