Answer:
Standard error
Step-by-step explanation:
The standard deviation of the distribution of sample means is called the standard error of the means.
It is denoted by: 
The standard error is calculated using the formula: 
where n is the sample size and 
is the population standard deviation.
B? I think ( do not come at me if it’s wrong)
-59 = -(b − -55)
Pretend that there is a -1 in front of the bracket.
-59= -1(b--55)
Multiply the bracket by -1
-59= -1(b)-1(--55)
-59= -b-55
Move -55 to the other side. Sign changes from -55 to 55
-59+55= -b-55+55
-59+55= -b
-4= -b
Multiply by -1
-4(-1)= -b(-1)
4= b
Answer: b= 4
To solve this, you would set up the equation to find the arithmetic mean of the data. This equation is (53+83+67+73+x)/5=70, where x=the score of the fifth exam. First, you combine the constants to get (276+x)/5=70. Then, multiply both sides by 5 to get rid of the denominator, to give you 276+x=350. Then subtract 276 from each side to get x=74. So, Thanh needs to score a 74 on his last exam to get a 70 in the class.
I would think c but I’m not completely sure sorry if it’s Wrong
