David made a scale model of the Sam Houston Statue. The statue has an actual height of 67 feet. David's model used a scale in wh
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Answer:
f(x)=8x-25
Step-by-step explanation:
Answer:
The 98% confidence interval for the variance in the pounds of impurities would be .
Step-by-step explanation:
1) Data given and notation
represent the sample variance
s=4 represent the sample standard deviation
represent the sample mean
n=20 the sample size
Confidence=98% or 0.98
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population mean or variance lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
The Chi square distribution is the distribution of the sum of squared standard normal deviates .
2) Calculating the confidence interval
The confidence interval for the population variance is given by the following formula:
On this case the sample variance is given and for the sample deviation is just the square root of the sample variance.
The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:
Since the Confidence is 0.98 or 98%, the value of and
, and we can use excel, a calculator or a table to find the critical values.
The excel commands would be: "=CHISQ.INV(0.01,19)" "=CHISQ.INV(0.99,19)". so for this case the critical values are:
And replacing into the formula for the interval we got:
So the 98% confidence interval for the variance in the pounds of impurities would be .
<h2>Answer with explanation:</h2>
By considering the given information, we have
Null hypothesis :
Alternative hypothesis :
Since the alternative hypothesis is two-tailed , so the test is a two-tailed test.
Given : Sample size : n= 20, since sample size is less than 30 so the test applied is a t-test.
;
Test statistic :
i.e.
Degree of freedom : n-1 = 20-1=19
Significance level = 0.01
For two tailed, Significance level
By using the t-distribution table, the critical value of t =
Since , the observed t-value (7.25) is greater than the critical value (2.861) .
So we reject the null hypothesis, it means we have enough evidence to support the alternative hypothesis.
We conclude that there is some significance difference between the mean score for sober women and 35.0.