Question

Which of the following types of data are likely to be normally distributed? Choose all that apply.

A. The driving distances of American commuters
B. The amount of popcorn that pops per bag
C. The outcomes of flipping a coin fifty times
D. The time it takes for an airliner to fly from Los Angeles to New York
E. The distance of an archer's shots from the center of a target

Answer 1

@ybarrap

Answer 2

?

Answer 3

Which of these would have an average a variance that is symmetrical about the mean. For A, some drivers go pretty far > 100 mi, but most people drive relatively short distances < 25 mi. For B, popcorn is pretty consistently pops an average number of kernels and you wouldn't expect there to be many more above the mean than below. For coins, you expect and average number of heads and tails so there could be 25 heads, sometimes more and sometimes fewer, but with only 50 flips, your not going to get a alot of outliers, normal distributions have pretty fat tails. The time to fly i would expect to be pretty consistent, no reason that delays should be more that being ahead. The errors around shooting a target is pretty symmetrical, you wouldn't expect errors one way or the other to be too high. There would be a fixed center with a well-defined variance.
So maybe B,D and E

Answer 4

I had D down

Answer 5

so wait I know its like a bell-shaped curve but... im not sure.. like I think u maybe right about B & E... but I don't understand why

Answer 6

is normally distributed like "EQUALLY DISTIBUTED" or NO?

Answer 7

with popcorn you have a well-defined mean and variance and you'll have a pretty good tail, too

Answer 8

but how do u know itll be tail? theres only 2 sides...

Answer 9

No. Uniformly distributed means that every case is equally likely and that's a flat distribution, not bell-shaped like normal.

Answer 10

u said something abt the tails? u weren't talking abt the coin flipping option right?

Answer 11

BUT THIS IS NORMAL DISTRIBUTION NOT UNIFORM

Answer 12

tails occur when you have outliers and most data will have outliers, but uniform, you have a fixed set of outcomes, with normal you have (-inf,inf) as the set of possible outcomes (theoretically)

Answer 13

okk. also I don't understand option A??

Answer 14

Right, we are determining if these random events are possibly normally distributed. Flipping of coins have two outcomes, heads tails -- they will be uniformly distributed -- two outcomes on the x-axis

Answer 15

what abt option a?

Answer 16

this is starting to make more sense now :p

Answer 17

whats so special abt American commuters

Answer 18

ok im gonna submit B, D, & E now!

Answer 19

I don't think that it would be normally distributed, it would be more exponential, because most people drive below the mean value and there are a few people that drive really far and would push the tail out. This would be a very asymmetric distribution.

Answer 20

ok.

Answer 21

I'm questioning D.

Answer 22

... I already submitted it

Answer 23

Because, you can count the number of heads and it will have an average with variance or you can count the number of heads and tail and the distribution will be uniform. It depends on how you count it. So there is a case for both uniform or normal depending on what outcomes you count.

Answer 24

ur post deleted? :/

Answer 25

jk. nvm

Answer 26

D isn't the coin one its the airliner one

Answer 27

here's my new question

Answer 28

\[z=\frac{ 127 - \mu }{ \sigma }\]

Answer 29

Familiar with this?

Answer 30

yea..

Answer 31

whats the denominator symbol mean?

Answer 32

so how do I plug this in? sorry I REALLY need to solve this, do one more problem, and then move on!!!!

Answer 33

@ybarrap ?

Answer 34

is the ans. -2.30?

Answer 35

@gypsy1274

Answer 36

@hihihii

Answer 37

is the ans. -2.30?

Answer 38

yes