Answer:
189 components must be sampled.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
That is z with a pvalue of 
, so Z = 2.575.
Now, find the margin of error M as such
Assume that component lifetimes are normally distributed with population standard deviation of 16 hours.
This means that 
How many components must be sampled so that a 99% confidence interval will have margin of error of 3 hours?
n components must be sampled.
n is found when M = 3. So
Rounding up:
189 components must be sampled.
Answer:
more than 15.40 cm and less than 14.60 cm
Step-by-step explanation:
A manufacturer of bolts has a quality control policy that requires it destroy any bolts that are more than 4 standard deviations from the mean.
mean length= 15 cm
standard deviation= 0.10 cm
4 standard deviation from mean= 15±(4×0.10)
therefore, bolts of length more than 15+0.4, and less than 15-0.4 will be destroyed
= 15.40 cm and 14.60 cm
Answer:
4/3 or 1 1/3
Step-by-step explanation:
Answer:
26
Step-by-step explanation:
Average = all the numbers added together then divided by the amount of numbers in the equation
21+24+25+25+26+26+26+26+27+29= 255
Since there are ten numbers in this equation, divide the sum by 10
25.5
round up
26
