Sarah loves farmers’ markets, but hates that they only accept cash. On one recent trip, she splurged on a $15.69 jar of honey. T
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Answer:
[0.7210,0.8189] = [72.10%, 81.89%]
Step-by-step explanation:
The sample size is
n = 200
the proportion is
p = 154/200 = 0.77
<em>Since both np ≥ 10 and n(1-p) ≥ 10 </em>
<em>We can approximate this discrete binomial distribution with the continuous Normal distribution. As the sample size is large enough, not applying the continuity correction factor makes no significant difference. </em>
The approximation would be to a Normal curve with this parameters:
<em>Mean </em>
p = 0.77
<em>Standard deviation </em>
The 90% confidence interval for the proportion would be then
where is the 10% critical value for the Normal N(0,1) distribution , this is a value such that the area under the N(0,1) curve outside the interval
is 10%=0.1
We can either use a table, a calculator or a spreadsheet to get this value.
In Excel or OpenOffice Calc we use the function
<em>NORMSINV(0.95) and we get a value of 1.645 </em>
The 90% confidence interval for the proportion is then
This means there is a 90% probability that the proportion of people who watch educational television is between 72.10% and 81.89%
If the television company wanted to publicize the proportion of viewers, do you think it should use the 90% confidence interval?
Yes, I do.
After 20 minutes Clint is on page = 151
After 45 minutes Clint is on page = 181
Time slot = minutes
Difference in pages in 25 minutes = pages.
Lets suppose Clint is reading each page at same pace.
So , In 25 minutes, he can read = 30 pages
In 1 minute he can read = pages
Initial time is 20 minutes, so he can read the number of pages in 20 minutes =
So, number of pages Clint read prior to study hall were =
pages.