Now Cathy is three times as old as Katie. In six years Cathy will be only twice as old as Katie. How old is each girl now?
1 answer:
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Answer:
626 and 654
Step-by-step explanation:
Given that a television sports commentator wants to estimate the proportion of citizens who "follow professional football."
Part I:
p = 0.48
Margin of error =
Sample size should be >626
Part II:
If unknown we take p = 0.5 because maximum std error for this
Here everything would be the same except insted of 0.48 we use 0.5
Margin of error =
-------------------------
a and b are too close because 0.46 proportion is close to part b proporti0n 0.5
Bernard’s walking speed is 140 meters per minute
Bernard’s walking speed is 8.4 kilometers per hour
Step-by-step explanation:
The pace length P is the distance between the rear of two consecutive footprints
The formula, n P = 140, gives an approximate relationship between n and P where,
- n = number of steps per minute
- P = pace length in meters
- Bernard knows his pace length is 0.80 meters
- The formula applies to Bernard’s walking
We need to calculate Bernard’s walking speed in meters per minute and in kilometers per hour
∵ n = number of steps per minute
∴ n unit is number / minute
∵ P = pace length in meters
∴ P unit is meter
- That means n P unit is meters/minute
∴ n P represents the speed in meters per second
∵ The formula applies to Bernard’s walking
∵ His pace length is 0.80 meters
∵ n P = 140
∴ n(0.8) = 140
- Divide both sides by 0.8
∴ n = 175
- That means he moves 175 steps per minute
∵ The distance he walks in minute = 175 × 0.8 = 140 meters/minute
∴ His speed is 140 meters per minute
Bernard’s walking speed is 140 meters per minute
∵ 1 km = 1000 m
∵ 1 hour = 60 minutes
- Divide the meters by 1000 and the minute by 60 to change
from meters per minute to kilometers per hour
∴ His walking speed = ÷
- Change ÷ to × and reciprocal the fraction after the division sign
∴ His walking speed = ×
= 8.4 km/h
Bernard’s walking speed is 8.4 kilometers per hour
Learn more:
You can learn more about the speed in brainly.com/question/5461619
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