The answer will be Mean = 135 Variance = 62 and Standard Deviation = 8
<h3>What is the standard deviation? </h3>
Standard deviation is defined as the amount of variation or the deviation of the numbers from each other.
Given that :
Proportion (p) = 54%
Sample size (n) = 250
Using Normal approximation :
Mean = np
Mean = 250 * 0.54 = 135
Variance = npq ; q = 1 - p = 1 - 0.54 = 0.46
Variance = (250 * 0.54 * 0.46) = 62.1 = 62
Standard deviation = √variance = √62.1
Standard deviation = 7.8803553 = 8
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Answer:
53.2 mph
Step-by-step explanation:
Mara's family travels 239.4 miles between the hours of 9:10 a.m. to 1:40 p.m.
1:40 p.m. is 13:40.
Thus, they traveled for
13 hours 40 minutes - 9 hours 10 minutes = 4 hours 30 minutes
that is hours.
Use formula:
where
D = distance
r = rate
t = time.
In your case,
D = 239.4 miles
t = 4.5 hours