Answer:
- 39 quarters and 41 nickels
Step-by-step explanation:
Let the number of quarters be x and nickels be y.
<u>Given:</u>
- Quarter is 25 cents
- Nickel is 5 cents
- Number of coins is 80
- Total amount is $11.80 = 1180 cents
<u>We have equations:</u>
- x + y = 80
- 25x + 5y = 1180
<u>Solve the system by elimination, subtract 5 times the first equation from the second one:</u>
- 25x + 5y - 5x - 5y = 1180 - 80*5
- 20x = 780
- x = 780/20
- x = 39
<u>Find the value of y:</u>
- 39 + y = 80
- y = 80 - 39y = 41
<u>Verify:</u>
- 25*39 + 5*41 = 975 + 205 = 1180
2 5/6 = 2.83
1 3/4 = 1.75
2.83*1.75= 4.9525
Answer:
7
Step-by-step explanation:
σ = 4 ; μ =?
8.52 to the left of X
.
P(X < 8.52) = 64.8%
P(X < 8.52) = 0.648
Using the Z relation :
(x - μ) / σ
P(Z < (8.52 - μ) / 4)) = 0.648
The Z value of 0.648 of the lower tail is equal to 0.38 (Z probability calculator)
Z = 8.52 - μ / 4
0.38 = 8.52 - μ / 4
0.38 * 4 = 8.52 - μ
1.52 = 8.52 - μ
μ = 8.52 - 1.52
μ = 7
Answer:
0.8 cm
Step-by-step explanation:
The formula for MAD is attached in the picture.
x_i are the values (data)
x bar is the mean
n is the number of numbers (data)
For figuring out MAD, basically, <em>we subtract the mean from each of the values respectively and take the absolute value and SUM for all of the numbers in the data set. Then we divide by n, the number of numbers.</em>
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Let's do this:
MAD = 
MAD is 0.8
