Please help me. Will mark brainliest. A.S.A.P
1 answer:
Answer:
D. 274
Step-by-step explanation:
A normal distribution of the scores is assumed. In the figure attached, the standard normal distribution table is shown.
If only top 5% of athletes are part of the team, then we need to find the value of the table which has a probability of 95%, that value is between 1.64 and 1.65, so we interpolate it as 1.645. The table was made for a variable with mean = 0 and standard deviation (sd) equal to 1, therefore to refer the result to our variable we compute:
1.645 = (x - mean)/sd
x = 1.645*sd + mean
x = 1.645*15 + 250 ≈ 274
So, 95% of the scores are below 274, then 274 is the minimum qualifying score
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Answer:
the probability the person's reaction time will be between 0.9 and 1.1 seconds is 0.0378
Step-by-step explanation:
Given the data in the question;
the cumulative distribution function F(x) = ;
probability the person's reaction time will be between 0.9 and 1.1 seconds
P( 0.9 < x < 1.1 ) = P( x ≤ 1.1 ) - P( x ≤ 0.9 )
P( 0.9 < x < 1.1 ) = F(1.1) - F(0.9)
= [ ] - [
]
we substitute
= [ ] - [
]
= [ ] - [
]
= [ ] - [
]
= [ 1 - 0.1079796998 ] - [ 1 - 0.1457938 ]
= 0.8920203 - 0.8542062
= 0.0378
Therefore, the probability the person's reaction time will be between 0.9 and 1.1 seconds is 0.0378