What is 2 times (-2a-7) equal to
2 answers:
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Answer:
Step-by-step explanation:
We have to find the system in which we can use the x and y from the given system of equations and make it hold true
From the given equations:
multiply top equation by -2 and add them
so, x = 6, y = 5
A: x-y = 2
6 - 5 = 1, so its not a
B: -2x + 2y = -2
-2(6) + 2(5) = -12 + 10 = -2
B works
just looking at C and D I can tell it doesnt work
So the answer is B
Answer:
Between the lower-bound of 117 mg/dl and the upper bound of 137 mg/dl.
Step-by-step explanation:
Empirical Rule
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
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
.
In this question:
Mean of 127, standard deviation of 10.
For the sample mean:
By the Central Limit Theorem, mean is 127, while the standard deviation is
According to the empirical rule, in 95 percent of samples the SAMPLE MEAN blood-glucose level will be between?
By the Empirical Rule, within 2 standard deviations of the mean. So
127 - 2*5 = 117 mg/dl
127 + 2*5 = 137 mg/dl.
Between the lower-bound of 117 mg/dl and the upper bound of 137 mg/dl.