I’m confuse I need help
2 answers:
You might be interested in
Part A:
The probability that a normally distributed data with a mean, μ and standard deviation, σ is greater than a given value, a is given by:
Given that the average precipitation in Toledo, Ohio for the past 7 months is 19.32 inches with a standard deviation of 2.44 inches, the probability that <span>a randomly selected year will have precipitation greater than 18 inches for the first 7 months is given by:
Part B:
</span>The probability that an n randomly selected samples of a normally distributed data with a mean, μ and standard deviation, σ is greater than a given value, a is given by:
Given that the average precipitation in Toledo, Ohio for the past 7 months is 19.32 inches with a standard deviation of 2.44 inches, the probability that <span>5 randomly selected years will have precipitation greater than 18 inches for the first 7 months is given by:
</span>
The probability that a normally distributed data with a mean, μ and standard deviation, σ is greater than a given value, a is given by:
Given that the average precipitation in Toledo, Ohio for the past 7 months is 19.32 inches with a standard deviation of 2.44 inches, the probability that <span>a randomly selected year will have precipitation greater than 18 inches for the first 7 months is given by:
Part B:
</span>The probability that an n randomly selected samples of a normally distributed data with a mean, μ and standard deviation, σ is greater than a given value, a is given by:
Given that the average precipitation in Toledo, Ohio for the past 7 months is 19.32 inches with a standard deviation of 2.44 inches, the probability that <span>5 randomly selected years will have precipitation greater than 18 inches for the first 7 months is given by:
</span>
Using hypothesis test, we conclude that there is evidence to believe that the average household income has increased.
According to the question,
The average household income for a recent year (x₁⁻) = $30,000
The average household income for a recent year (x₂⁻) = $24,500
sample sizes n₁ = n₂ = 34
standard deviation of both samples were $24,500. Thus, s₁ = s₂ = $5928.
Null hypothesis: There is no evidence to believe that the average household income has increased.
H₀ : μ₁ ≤ μ₂
Alternative hypothesis: There is evidence to believe that the average household income has increased.
H₁: μ₁ > μ₂
To check hypothesis we have the formula
Standard error=
=
= 1437.7512
Thus, standard error is $1437.7512.
Formula for test statistic = [(x₁⁻ - x₂⁻) - (μ₁ - μ₂)]/standard error
= [(30000 - 24500) - 0]/1437.7512
= 3.8254
The critical value of z at 5% level of significance is 1.6449.
Here, the calculated value is greater than the critical value so we reject H₀.
Hence using hypothesis test, we conclude that there is evidence to believe that the average household income has increased.
Learn more about hypothesis test here
#SPJ2