Answer: The person's speed is 8 miles per hour.
Step-by-step explanation:
To solve we want to convert the and
proportionally for the number of miles per hour. We know that multiplying a fraction by its reciprocal will equal 1. So let's do that for the value of the hour.
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Since we multiplied that to the number of hours we must also do that for the number of miles.
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Answer:
The 95% CI for the difference of means is:
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>"Find a 95% confidence interval on the difference of the towels mean absorbency produced by the two processes. Assumed that the standard deviations are estimated from the data. Round to two decimals places."</em>
Process 1:
- Sample size: 10
- Mean: 200
- S.D.: 15
Process 2:
- Sample size: 4
- Mean: 300
- S.D.: 50
The difference of the sample means is:
The standard deviation can be estimated as:
The degrees of freedom are:
The t-value for a 95% confidence interval and 12 degrees of freedom is t=±2.179.
Then, the confidence interval can be written as:
Answer:
a) It can be used because np and n(1-p) are both greater than 5.
Step-by-step explanation:
Binomial distribution and approximation to the normal:
The binomial distribution has two parameters:
n, which is the number of trials.
p, which is the probability of a success on a single trial.
If np and n(1-p) are both greater than 5, the normal approximation to the binomial can appropriately be used.
In this question:
So, lets verify the conditions:
np = 201*0.45 = 90.45 > 5
n(1-p) = 201*(1-0.45) = 201*0.55 = 110.55 > 5
Since both np and n(1-p) are greater than 5, the approximation can be used.