Answer: in 95% of races, his finishing time will be between 62 and 64 seconds.
Step-by-step explanation:
The empirical rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below
68% of data falls within the first standard deviation from the mean.
95% fall within two standard deviations.
99.7% fall within three standard deviations.
From the information given, the mean is 63 seconds and the standard deviation is 5 seconds.
2 standard deviations = 2 × 0.5 = 1
63 - 1 = 62 seconds
63 + 1 = 64 seconds
Therefore, in 95% of races, his finishing time will be between 62 and 64 seconds.
Answer:
P(Y ≥ 15) = 0.763
Step-by-step explanation:
Given that:
Mean =135
standard deviation = 12
sample size n = 50
sample mean
= 140
Suppose X is the random variable that follows a normal distribution which represents the weekly supermarket expenses
Then,

The probability that X is greater than 140 is :
P(X>140) = 1 - P(X ≤ 140)



From z tables,


Similarly, let consider Y to be the variable that follows a binomial distribution of the no of household whose expense is greater than $140
Then;


∴
P(Y ≥ 15) = 1- P(Y< 15)
P(Y ≥ 15) = 1 - ( P(Y=0) + P(Y=1) + P(Y=2) + ... + P(Y=14) )

P(Y ≥ 15) = 0.763
Answer:
The Ballwin Bears are taller on average, and the Aviston Aces have players whose heights are more consistent.
Step-by-step explanation:
for derby dragon;
mean height = 72 inches
standard deviation = 1.2 inches
for aviston aces:
mean height = 70.8
standard deviation = 0.7 inches
for balwin bears;
mean height = 73 inches
standard deviation = 1.0 inches
the mean height of aviston aces < mean height of derby < mean height of balwin bears
So on average the balwin bears are taller.
The standard deviation of derby dragon is > that of balwin bears > aviston aces.
So the more consistent height is that of aviston aces players.
Answer: 11.4%
Step-by-step explanation:
100% of your life is 57 years
?% will be 6.5 years?
this is a simple ratio problem:
57 --> 100%
6.5 ---> (6.5 x 100)/57 ≅ 11.4%
You have known the person for about 11.4% of your life.
Pretty sure it’s y= 5 + 1.95x
I don’t think that the number of people matters because the cost doesn’t vary based on the number of people