Answer:
7.64% probability that they spend less than $160 on back-to-college electronics
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

Probability that they spend less than $160 on back-to-college electronics
This is the pvalue of Z when X = 160. So



has a pvalue of 0.0763
7.64% probability that they spend less than $160 on back-to-college electronics
<span>x cubed +3x squared - 4x= 0
= x^3 + 3x^2 -4x = 0
=x(x^2 +3x -4) = 0
= x (x+4)(x-1) = 0
x = 0
x+ 4 = 0 then x = -4
x - 1 = 0 then x = 1
answer: x = 0, x = -4 and x = 1</span>
Answer:
The experimental probability of the coin landing tails-side up is <u>60</u><u>%</u><u>.</u>
Step-by-step explanation:
The probability of it landing heads up is 4/10. You can use 4/10 to find how many times it landed on tails.
10/10 - 4/10= 6/10 now convert 6/10 into a percentage, 60/100=<u>60%</u>
Write it out as a set of equation:
Let x be number of 8 cent stamps, y be 10 cent stamps, and z be 2 cent stamps.
x=y
z=x+y
8x+10y+2z=440
Lets first solve for x:
from x=y and z=2x(from first equation) the last equation is
8x+10x+4x=440
22x=440
x=20
know that x=20, you also know that y=20 as well, since z=x+y, z=40.
So 20 8-cent stamps, 20 10-cent stamps, and 40 2-cent stamps.
Answer:
$2.56
Step-by-step explanation:
If you multiply 12.82 by .20, you would get 2.564. Then you just round it up and the answer you get is $2.56. Hope this helps!