Answer:
x = 25
Step-by-step explanation:
2/5x - 1 = 9
Add 1 to both sides
2/5x = 10
Multiply by 5 on both sides
2x = 50
Divide by 2 on both sides
x = 25
Check the answer:
Plug in 25 for x
2/5(25) - 1 = 9
10 - 1 = 9
9 = 9
The answer is correct.
<span>3 is 1.0 below the mean. That is 1.0 / 0.9, or 1.1111... standard deviations below the mean.
So look up z < -1.11 on your graphing calculator.
It should be around 0.1335 or 13.35%</span>
Answer: d=3
Step-by-step explanation: 3 times 3 is 9
9 times 3 is 27
Answer:
By the Central Limit Theorem, the sampling distribution is approximately normal, with mean 30 and standard deviation 0.1.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean
and standard deviation 
The batteries produced in a manufacturing plant have a mean time to failure of 30 months with a standard deviation of 2 months.
This means that 
Sample of 400 batteries. The sampling distribution of is approximately:
So 
By the Central Limit Theorem, the sampling distribution is approximately normal, with mean 30 and standard deviation 0.1.
He is incorrect because he should have 6 factors of 9.