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
Divide the price by the number of payments.
$15,480/36 = $430
G(x) = ax^2
y = ax^2
5 = a(1)^2
a = 5
Therefore, g(x) = 5x^2
Answer:
Population mean = 7 ± 2.306 × 
Step-by-step explanation:
Given - A university researcher wants to estimate the mean number
of novels that seniors read during their time in college. An exit
survey was conducted with a random sample of 9 seniors. The
sample mean was 7 novels with standard deviation 2.29 novels.
To find - Assuming that all conditions for conducting inference have
been met, which of the following is a 94.645% confidence
interval for the population mean number of novels read by
all seniors?
Proof -
Given that,
Mean ,x⁻ = 7
Standard deviation, s = 2.29
Size, n = 9
Now,
Degrees of freedom = df
= n - 1
= 9 - 1
= 8
⇒Degrees of freedom = 8
Now,
At 94.645% confidence level
α = 1 - 94.645%
=1 - 0.94645
=0.05355 ≈ 0.05
⇒α = 0.5
Now,

= 0.025
Then,
= 2.306
∴ we get
Population mean = x⁻ ±
×
= 7 ± 2.306 × 
⇒Population mean = 7 ± 2.306 × 