Juan makes a measurement in a chemistry laboratory and records the result in his lab report. The standard deviation of students'
lab measurements is σ σ = 10 milligrams. Juan repeats the measurement 4 times and records the mean x x of his 4 measurements.
1 answer:
Answer:
The question is incomplete, but here is the complete part of the question; What is the standard deviation (±0.01) of Juan's mean result? (That is, if Juan kept on making 4 measurements and averaging them, what would be the standard deviation of all his x⎯⎯ 's?) How many times must Juan repeat the measurement so that the standard deviation of x⎯⎯ is 3? (Round your answer to the nearest whole number.)
Standard deviation of his measurement = 5
minimum number of measurement = 12
Step-by-step explanation:
The concept of standard error of mean is applied here which is the approximate standard deviation of a sample distribution or in a normal distribution. Mathematically, Standard error is given as SE = s/√n, where n is the sample size.
The equation implies that the sample error increases as the sample size decreases and vice versa.
The step y step calculation is shown below
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Answer:
- 17,750
- 1737
Step-by-step explanation:
A suitable table or calculator is needed.
One standard deviation from the mean includes 68.27% of the total, so the number of bottles in the range 20 ± 0.16 ounces will be ...
0.6827·26,000 = 17,750 . . . . . within 20 ± 0.16
__
The number below 1.5 standard deviations below the mean is about 6.68%, so for the given sample size is expected to be ...
0.66799·26,000 = 1737 . . . . . below 19.76
_____
<em>Comment on the first number</em>
The "empirical rule" tells you that 68% of the population is within 1 standard deviation (0.16 ounces) of the mean. When the number involved is expected to be expressed to 5 significant digits, your probability value needs better accuracy than that. To 6 digits, the value is 0.682689, which gives the same "rounded to the nearest integer" value as the one shown above.
Answer:
The best estimate of the area of the larger figure is
Step-by-step explanation:
step 1
<em>Find the scale factor</em>
we know that
If two figures are similar, then the ratio of its corresponding sides is equal to the scale factor
Let
z----> the scale factor
x-----> the corresponding side of the larger figure
y-----> the corresponding side of the smaller figure
so
we have
substitute
-----> the scale factor
step 2
<em>Find the area of the larger figure</em>
we know that
If two figures are similar, then the ratio of its areas is equal to the scale factor squared
Let
z----> the scale factor
x-----> the area of the larger figure
y-----> the area of the smaller figure
so
we have
substitute and solve for x