Answer:

Step-by-step explanation:
90 + 40 = 130
180 - 130 = 50
Answer:
75?
Step-by-step explanation:
1/4 = 25
25 x 3 =75
----
3/4=75
C+a=166
a=166-c
5.3c+9.2a=1254.2
5.3c+9.2(166-c)=1254.2
5.3c+1527.2-9.2c=1254.2
5.3c-9.2c=1254.2-1527.2
-3.9c=-273
c=-273/-3.9
c=70
Hope this helps!
Answer: 2.76 g
Step-by-step explanation:
The formula to find the standard deviation:-

The given data values : 560 g, 562 g, 556 g, 558 g, 560 g, 556 g, 559 g, 561 g, 565 g, 563 g.
Then, 
Now, 
Then, 
Hence, the standard deviation of his measurements = 2.76 g