Answer:
This mileage interval is from 30120 miles and higher.
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 problem, we have that:
All he knows is that, for a large number of tires tested, the mean mileage was 25,000 miles, and the standard deviation was 4000 miles. This means that 
.
A manufacturer of tires wants to advertise a mileage interval that ex-cludes no more than 10% of the mileage on tires he sells. What interval wouldyou suggest?
The lower end of this interval is X when Z has a pvalue of 0.90. That is 
.
So
This mileage interval is from 30120 miles and higher.
Answer:
You have the two numbers, so 36/60 is the ratio of boys to girls.
Step-by-step explanation:
You will want to simplify those numbers (reduce to lowest terms).
Answer:
3
Step-by-step explanation:
Answer: The least score she can get on her next test is 455 points.
Step-by-step explanation: From the available information, her current mean score is 88%, and that was achieved from a total of 5 tests. Hence, her mean score was computed as follows;
Mean = (Summation of data)/observed data
Where the observed data is 5 and the mean is 88. Therefore the mean can now be expressed as,
88 = Summation of data/5
By cross multiplication we now have
88 x 5 = Summation of data
440 = Summation of data.
So, if she wants to raise her mean score on her next test to 91%, her least possible score would be derived as
91 = (Summation of data)/5
By cross multiplication we now have
91 x5 = Summation of data
455 = Summation of data
Therefore, on her next test, she must score at least 455 points.
They should still be 280 miles apart on the map i belive.
