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:
option 1 i believe
Step-by-step explanation:
just worked it out
i hope this is right and helps <3
Answer:
The degrees of freedom are given by:

The significance level is
and then the critical value can be founded in th chi square table we need a quantile that accumulates 0.05 of the area in the right tail of the distribution and for this case is:

And if the chi square statistic is higher than the critical value we can reject the null hypothesis in favor of the alternative.
Step-by-step explanation:
We have the followign system of hypothesis:
Null hypothesis: 
Alternative hypothesis: 
The degrees of freedom are given by:

The significance level is
and then the critical value can be founded in th chi square table we need a quantile that accumulates 0.05 of the area in the right tail of the distribution and for this case is:

And if the chi square statistic is higher than the critical value we can reject the null hypothesis in favor of the alternative.
Answer:
P = 1 / 6
Step-by-step explanation:
Given:-
- A deck has 500 cards
- Numbered from 1-500
Find:-
you are asked to pick three cards, one at a time, what's the probability of each subsequent card being larger than the previous drawn card
Solution:-
- Suppose we draw three cards. We don't care what they actually are, irrespective of number.
- Let the three numbers be a, b, c: Such that:
a < b < c.
- The total possible combinations with 3 numbered cards will be:
a b c
b a c
a c b
b a c
b c a
c a b
- We have 6 possibilities for 3 numbered cards. So the probability of of each subsequent card being larger than the previous drawn card would be:
P = 1 / possible combinations
P = 1 / 6