Answer:
The score that separates the lower 5% of the class from the rest of the class is 55.6.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question:
Find the score that separates the lower 5% of the class from the rest of the class.
This score is the 5th percentile, which is X when Z has a pvalue of 0.05. So it is X when Z = -1.645.
The score that separates the lower 5% of the class from the rest of the class is 55.6.
I've actually just learned this. We would set up the proportion as X/9=36/X so after we cross multiply we get x^2=324. Then we find the square root of both sides to simplify. And using my calculator the square root of x^2 is just x. And the square root of 324 is 18. So the final answer is x=18 or the geometric mean is 18.
Answer:
a. H0:μ1≥μ2
Ha:μ1<μ2
b. t=-3.076
c. Rejection region=[tcalculated<−1.717]
Reject H0
Step-by-step explanation:
a)
As the score for group 1 is lower than group 2,
Null hypothesis: H0:μ1≥μ2
Alternative hypothesis: H1:μ1<μ2
b) t test statistic for equal variances
t=(xbar1-xbar2)-(μ1-μ2)/sqrt[{1/n1+1/n2}*{((n1-1)s1²+(n2-1)s2²)/n1+n2-2}
t=63.3-70.2/sqrt[{1/11+1/13}*{((11-1)3.7²+(13-1)6.6²)/11+13-2}
t=-6.9/sqrt[{0.091+0.077}{136.9+522.72/22}]
t=-3.076
c. α=0.05, df=22
t(0.05,22)=-1.717
The rejection region is t calculated<t critical value
t<-1.717
We can see that the calculated value of t-statistic falls in rejection region and so we reject the null hypothesis at 5% significance level.
Answer:
2.55
Step-by-step explanation:
To find the radius, the formula is:
R = C/2 x pi
pi = 3.14
16/(2 x 3.14) = 2.54648
= 2.55
<u>ANSWER</u>
The correct answer is A
<u>EXPLANATION</u>
To find the ink cost of each card coming from printer B, we need to find the total cost from printer B and the total number of cards printed by Printer B.
The total hours of all the three printers over the three weeks
The total hours of printer B only
Total number of cards produced over the three weeks
We can use ratio and proportion to determine the total cards produce by printer B only.
If less, more divides
Total cost of Printer B in 130 hours
$
The ink cost
$
to 2 decimal places
