Answer:
The last guy's height is 69 inches
Step-by-step explanation:
mean=sum of all numbers/number of numbers
There are 5 numbers in the set which means that 65 is the sum of all five numbers divided by 5. To reverse that we multiply 65 by 5 to get the sum of all of the numbers.
325 is the sum of all of the numbers so to find the missing number you add up all of the known numbers in the set and find the difference between that sum and 325.
The missing guy's height is 69 inches.
Answer:
If the warranty limits are at 41.12 months, only 10 percent of the HDTVs need repairs at the manufacturer's expense.
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:
For a new HDTV the mean number of months until repairs are needed is 36.84 with a standard deviation of 3.34 months. This means that .
Where should the warranty limits be set so that only 10 percent of the HDTVs need repairs at the manufacturer's expense?
This is the value of X when Z has a pvalue of 0.90.
Looking at the z-table, we get that this is between and
, so we use
.
If the warranty limits are at 41.12 months, only 10 percent of the HDTVs need repairs at the manufacturer's expense.