The answer is a because if you divide 1000 by 2 you get 500 and the other ones you get a decimal.
The answer is B because in total you there are 15 bicycles and tricycles so b +t =15
Bicycles have 2 wheels and tricycles have 3 wheels so 2b + 3t = 45
A)
B)
We first find the z-score associated with the level of confidence. For 95% confidence:
Convert 95% to a decimal: 0.95
Subtract from 1: 1-0.95 = 0.05
Divide by 2 (this is the area in the tails): 0.05/2 = 0.025
Subtract from 1 (we don't want the tails, we want the area in the middle): 1-0.025 = 0.975
Using a z-table (http://www.z-table.com) we find the z-score for this is 1.96. We now use the formula
For a 98% confidence level:
Convert 98% to a decimal: 0.98
Subtract from 1: 1 - 0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1 - 0.01 = 0.99
Using the z-table we see the closest number to this is for the z-score 2.33:
Answer:
volume of air = 3200 m³
Explanation:
We are given that 1 m³ of hot air can lift a mass of about 0.25 kg.
To find the volume of hot air required to lift a mass of 800 kg, we will simply use cross multiplication as follows:
1 m³ ..................> 0.25 kg
?? .....................? 800 kg
volume of hot air required = (800*1) / (0.25)
volume of hot air required = 3200 m³
Hope this helps :)