Answer:
r = <u>26</u>
Step-by-step explanation:

Answer:
b. Kathy
Step-by-step explanation:
We compare each of their score by how far away from the mean when in term of the standard deviation. Using the following formula

For John he is (85 - 75)/5 = 2.
For Kathy she is (80 - 50)/10 = 3.
Since Kathy is 3 standard deviation better than her class' average, while John is only 2's. We conclude that Kathy did better.
9514 1404 393
Answer:
300
Step-by-step explanation:
There are 25 ways to select the first student. After that student is removed from the selection pool for the second student, there are 24 ways to select the second student. This gives 25·24 = 600 ways to select 2 students <em>in a particular order</em>.
Since we don't care about the order, we can divide this number by the number of ways two students can be ordered: AB or BA, 2 ways.
600/2 = 300
There are 300 ways to pick a combination of two students from 25.
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<em>Additional comments</em>
This sort of selection (2 out of 25) has a formula for it, and an abbreviation for the formula.
"n choose k" can be written nCk or C(n, k)
The function is a ratio of factorials:
nCk = n!/(k!(n-k)!)
If you can typeset this, it is written ...

This is different from the formula for the number of <em>permutations</em> of n things taken k at a time. That would be written nPk or P(n, k) = n!/(n-k)!.
Answer:
The answer is D.
Step-by-step explanation:
It is given that Gabriella swims 2 laps for 1 minute. So in order to find how many minutes did he swim for each lap, you have to divide it by 2 :
2 laps = 1 minute
2 laps ÷ 2 = 1 minute ÷ 2
1 lap = 1/2 minute
= 30 seconds
Test :
Gabriella swim 1/2 min per lap. So if he swim 2 laps, you have to multiply it by 2 :
1/2 × 2 = 1 minute
<span>he box plots below show attendance at a local movie theater and high school basketball games:
two box plots shown. The top one is labeled Movies. Minimum at 60, Q1 at 65, median at 95, Q3 at 125, maximum at 150. The bottom box plot is labeled Basketball games. Minimum at 90, Q1 at 95, median at 125, Q3 at 145, maximum at 150.
Which of the following best describes how to measure the spread of the data?
The IQR is a better measure of spread for movies than it is for basketball games.
The standard deviation is a better measure of spread for movies than it is for basketball games.
The IQR is the best measurement of spread for games and movies.
The standard deviation is the best measurement of spread for games and movies.</span>