1)
probability of 5 tails = (1/2)^5 = 1/32
so probability of any other number than 5 = 1 - 1/32 = 31/32
Yes, D
2)6 letters
6! = 6*5*4*3*2*1 = 720
yes B
3)Well, if by middle they mean middle in the order they gave you with summer in the middle, I agree that A is worst.
However I rearranged the data:
arrange the 12 in order to see what histogram would look like
48 48 50 51 53 61 65 73 77 82 82 85
Well, the mode is either the two at 48 or the two at 82. Neither cluster is very representative so I would say the mode was worst now, C
4) well first find the mean
mu = (1/12)[sum]
= (1/12)(115829 )=
64.6
which since they are rounding to degrees I will call:
mu = 65
Now
s^2 = (1/11) * sum of (x-mu)^2
so x-mu first
-17 -17 -15 -14 -12 -4 0 8 12 17 17 20
so then squared
289 289 225 196 144 16 0 64 144 289 289 400
so
(1/11)(2345) = 213
so s^2 = variance = 213
well they used division by n, 12, while I used the more accepted division by (n-1) or 11
If I had used 12 then
s^2 = 195.4
which is D, agree with you
5)s = sqrt (195.4) =13.9
so Yes, B
1)A coin is tossed 5 times. Find P(at most 4 tails.)
A)3/16
B)13/16
C)1/32
D)31/32
I chose D
2)How many different arrangements of the letters of the word doodle are possible?
A)180
B)720
C)15
D)90
I chose B
For #3-5, use the following tepereatures from Jan-Dec: 50,48,51,65,77,85,82,82,73,61,53,48
3)Which measure of central tendency is not a good representation of the data?
A)middle
B)median
C)mode
D)mean
I chose A
4)Find the variance of the temperatures.
A)4366.2
B)64.6
C)2342.9
D)195.2
I chose D
5)Find the standard deviation of the temperatures.
A)14.6 degrees Fahrenheit
B)14.0 degrees Fahrenheit
C)63.0 degrees Fahrenheit
D)64.6 degrees Fahrenheit
I chose B
3 answers
i need to learn probability & statistics. completly.
coin die (coin,die
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3 answers