Answer:
option (c) n = 201
Step-by-step explanation:
Data provided in the question:
Standard deviation, s = 5.5 ounce
Confidence level = 99%
Length of confidence interval = 2 ounces
Therefore,
margin of error, E = (Length of confidence interval ) ÷ 2
= 2 ÷ 2
= 1 ounce
Now,
E =
here,
z = 2.58 for 99% confidence interval
n = sample size
thus,
1 =
or
n = (2.58 × 5.5)²
or
n = 201.3561 ≈ 201
Hence,
option (c) n = 201
Given:
An athlete who makes laps in 3 mins 45 seconds on a 400m field.
To find:
The speed of the athlete in m/s.
Solution:
We know that,
Distance covered in 1 lap = 400 m
Distance covered in laps =
m
= m
= m
We know that,
1 minute = 60 seconds
3 minutes = 180 seconds
3 minutes 45 second = 180 + 45 seconds
= 225 second
The speed of the athlete is:
Therefore, the speed of the athlete is about 8.44 m/s.