1776 & Eggs
You flip a coin and roll a dice. Find the probability that you flip a tails and roll a 3.
1/12 = 8.33%
Page 385 #20 #a) i) = ?
68%
My data has a mean of 54 meters. I changed it to cm (times by 100). What's the new mean?
5,400 cm
What is the empirical rule?
68-95-99.7
Fred goes to bed on time 70% of the time. When he goes to bed on time, 80% of the time he gets up on time. When he doesn't go to bed on time, he only gets up on time 10% of the time.
Organize the data in the most useful manner.
Tree diagram!
You have 10 cards numbered 1-10 in your pocket. If you draw one card, set it aside, and draw a second card, what is the probability that they are both even?
2/9 = 22.2%
Page 385 #20 #a) ii) = ?
Note: better wording: "If you're a Republican, what are the chances the voter favors stronger enforcement?"
30/37 = 81.1%
My data has a sd of 4 meters. I changed it to cm (times by 100). What's the new mean?
400 cm
What is the mean and standard deviation of the standard normal distribution (of z-scores)?
mean = 0, sd = 1
Fred goes to bed on time 70% of the time. When he goes to bed on time, 80% of the time he gets up on time. When he doesn't go to bed on time, he only gets up on time 10% of the time. What are the chances he goes to bed on time and gets up on time?
(0.70)*(0.80) = 56%
You draw one card from a standard 52-card deck, return it to the deck, and then draw a second. What is the probability that both cards are Hearts?
1/16 = 6.25%
Page 385 #20
What are the chances a voter is a Democrat and Opposes stronger enforcement?
11%
The high score in the class was 19/20. The scores are turned into percents. What is the new max?
95%
If the mean height of a male giraffe is 18' with a standard deviation of 2', what are the chances a male giraffe is 19.5' tall or taller?
22.7% (normalcdf)
What are the chances Fred wakes up on time?
56% + 3% = 59%
A bag contains 3 red, 5 blue, and 2 green marbles. If you draw one marble, set it aside, and the draw a second marble, find the probability that both marbles are red.
1/15 = 6.67%
Page 385 #20
Are being a Republican and Opposing stronger enforcement mutually exclusive?
No. 4% fit that description (not zero!)
The test scores had a median of 13. I used the formula
Grade = score*5 + 20
What is the median Grade?
85
If the mean height of a male giraffe is 18' with a standard deviation of 2', how short is the shortest 5%?
14.7'
What are the chances that Fred either wakes up on time, or goes to bed on time (or both)?
1 - 0.27 = 0.73
The average NBA player makes about 80% (or 4/5) of free throws. What is the probability of making two free throws in a row?
16/25 = 64%
Page 385 #20
Are being a Democrat and Opposing Stronger enforcement independent?
P(D) = 35%; P(D|O) = 50%, so NO!
or
P(O) = 22%; P(O|D) 31.4%, so NO!
The test scores had a range of 11. I used the formula
Grade = score*5 + 20
What is the range of the Grades?
55
If the mean height of a male giraffe is 18' with a standard deviation of 2', what is the IQR of giraffe height?
2.7'
19.35' - 16.65'
If Fred wakes up on time, what are the chances that he went to bed on time?
56/59 = 94.9%