Counting stragies
How would a student arrange 6 different books on the shelf
6!=720
find the mean of the average of the numbers 4, 6, 8, 10, and 12.
8
A z-score tells how many ______ a data value is from the mean.
standard deviations
In a normal distribution, approximately this percent of data falls within 1 standard deviation of the mean.
68%
Rewrite 34=81 in logarithmic form.
log3(81)=4
Choose a president, vice president, and secretary from 10 people
10P3=10!/(10-3)!=720
The middle value in the data set 3, 5, 7, 9, 11.
7
If a test score is 85, the mean is 75, and the standard deviation is 5, find the z-score.
85-75/5 = 2
In a normal distribution, approximately this percent of data falls within 2 standard deviations of the mean.
95%
In the sequence 3, 7, 11, 15, ..., this number is added each time to get the next term.
4
Choose 5 starting players from 12 basketball players
12C5=12!/5!7!=792
The most frequent value in the data set 2, 4, 4, 5, 6, 6, 6, 8.
6
A z-score of -1.5 means the value is 1.5 standard deviations ______ the mean.
below
In a normal distribution, approximately this percent of data falls within 3 standard deviations of the mean.
99.7%
2x+5≤17
x≤6
Award gold, silver, bronze, and fourth place to 12 runners
12P4=12!/8!=11,880
The difference between the highest and lowest values in the data set 12, 15, 18, 22, 27.
15
Student A has a z-score of 1.2 and Student B has a z-score of -0.8. Which student scored better relative to their group?
Student A
If 68% of data falls within 1 standard deviation of the mean, approximately what percent falls outside that range?
32%
x2−5x+6=0
x= 2, 3
Form a committee of 4 from 15 volunteers
15C4=15!/4!11!=1,365
This measure describes how spread out data values are from the mean.
Standard deviation
The mean is 50, the standard deviation is 10, and the z-score is 2. Find the data value.
50+2(10)
If 95% of data falls within 2 standard deviations of the mean, approximately what percent falls beyond 2 standard deviations from the mean?
5%
Factor x2−7x+12
(x-3)(x-4)