Answer:
standard error = 1.63
Step-by-step explanation:
To calculate the standard error we need to know the standard deviation (σ) and the sample size (n) (see the attached formula).
To obtain the standard deviation we use the given sample variance of 77.4 years:
σ²= variance
Therefore:
σ = √77.4 = 8.8
Now we can calcuate the estimated standard error:
standard error = σ /√n = 8.8/√29 = 1.63
The standard error gives us an estimation about how far the mean of the sample is from the mean of the entire population, and in this case is 1.63.
When they say quotient, they want a fraction, so the answer for that would be
and the decimal form of that would be 0.6. You can get that from dividing 6 by 10 and solving with long division.
Answer:
34 cm
Step-by-step explanation:
PR = PQ + QR
PQ = QR because Q is the mid-point
Since PQ = 17 cm, then QR = 17 cm
so,
PR = 17 + 17
PR = 34 cm
Answer:
1. 625,000 J
2. 100 J
4. 5 kg
5. √5 ≈ 2.236 m/s
Step-by-step explanation:
You should be aware that the SI derived units of Joules are equivalent to kg·m²/s².
To reduce confusion between <em>m</em> for mass and m for meters, we'll use an <em>italic m</em> for mass.
In each case, the "find" variable is what's left after we put the numbers into the formula. It is what the question is asking for. The "given" values are the ones in the problem statement and are the values we put into the formula. The formula is the same in every case.
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1. KE = (1/2)<em>m</em>v² = (1/2)(2000 kg)(25 m/s)² = 625,000 kg·m²/s² = 625,000 J
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2. KE = (1/2)<em>m</em>v² = (1/2)(0.5 kg)(20 m/s)² = 100 kg·m²/s² = 100 J
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4. KE = (1/2)<em>m</em>v²
250 J = (1/2)<em>m</em>(10 m/s)² = 50 m²/s²
(250 kg·m²/s²)/(50 m²/s²) = <em>m</em> = 5 kg
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5. KE = (1/2)<em>m</em>v²
2000 kg·m²/s² = (1/2)(800 kg)v²
(2000 kg·m²/s²)/(400 kg) = v² = 5 m²/s²
v = √5 m/s ≈ 2.236 m/s
