Answer:
The probability that Albert's sample of 64 will have a mean between 13.5 and 16.5 minutes is 0.9973.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Let X the random variable that represent interest on this case, and for this case we know the distribution for X is given by:
And let 
represent the sample mean, the distribution for the sample mean is given by:
On this case 
Solution to the problem
We are interested on this probability
If we apply the Z score formula to our probability we got this:
And we can find this probability on this way:
And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.
The probability that Albert's sample of 64 will have a mean between 13.5 and 16.5 minutes is 0.9973.
0.75(3.5a -6b)
= 0.75* (3.5a) -0.75* (6b) (distributive property)
= 2.625a -4.5b
The final answer is 2.625a -4.5b~
Answer: 3.5
Step-by-step explanation:
Given: Dimensions of larger prism = length of 4.2 cm, a width of 5.8 cm, and a height of 9.6 cm.
Dimensions of smaller prism = length of 14.7 cm, a width of 20.3 cm, and a height of 33.6 cm.
Scale factor = 
Since, smaller figure is the original figure and the bigger one is the image.
So, scale factor = 
[Taking lengths
Hence, the factor to produce the corresponding dimensions of the larger prism = 3.5
Answer: the probability that a randomly selected tire will have a life of exactly 47,500 miles is 0.067
Step-by-step explanation:
Since the life expectancy of a particular brand of tire is normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = life expectancy of the brand of tire in miles.
µ = mean
σ = standard deviation
From the information given,
µ = 40000 miles
σ = 5000 miles
The probability that a randomly selected tire will have a life of exactly 47,500 miles
P(x = 47500)
For x = 47500,
z = (40000 - 47500)/5000 = - 1.5
Looking at the normal distribution table, the probability corresponding to the z score is 0.067
