Answer:
30 cm²
Step-by-step explanation:
6*(4+6)/2=30 cm²
The question is incomplete! the complete question along with answer and step by step explanation is provided below.
Question:
A researcher records the repair cost for 8 randomly selected refrigerators. A sample mean of $57.89 and standard deviation of $23.69 are subsequently computed. Determine the 95% confidence interval for the mean repair cost for the refrigerators. Assume the population is approximately normal.
Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Step 2 of 2 : Construct the 95% confidence interval. Round your answer to two decimal places.
Given Information:
Sample mean repair cost = $57.89
Sample standard deviation = σ = $23.69
Sample size = 8
Confidence level = 95%
Required Information:
step 1: critical value = ?
step 2: 95% confidence interval = ?
Answer:
step 1: critical value = 2.365
step 2: 95% confidence interval = ($38.08, $77.70)
Step-by-step explanation:
Since the sample size is less than 30 and the standard deviation of the population is also unknown therefore, we can use the t-distribution to find the required confidence interval.
The confidence interval is given by
Where is the mean repair cost and MoE is the margin of error that is given by
Where n is the sample size, s is the sample standard deviation, and is the t-score corresponding to 95% confidence level.
The t-score corresponding to 95% confidence level is
Significance level = 1 - 0.95 = 0.05/2 = 0.025
Degree of freedom (DoF) = n - 1 = 8 - 1 = 7
From the t-table at α = 0.025 and DoF = 7
t-score = 2.365
Therefore, the critical value that should be used in constructing the confidence interval is 2.365
So the required 95% confidence interval is
Therefore, we are 95% confident that the mean repair cost for the refrigerators is within the range of ($38.08, $77.70)
Answer:
x=3 or -3
Step-by-step explanation:
hope it helps
Answer:
y<2
Step-by-step explanation:
Subtract 2 on both sides
Answer:
y<2
Step-by-step explanation:
Answer:
89
Step-by-step explanation:
Given Information:
Annual interest rate = r = 12%
Principal amount = P = $1000
Number of years = t = 3
Required Information
Accumulated amount = A = ?
Answer:
Annual compounding = A = $1404.93
Semi-annuall compounding = A = $1418.52
Quarterly compounding = A = $1425.76
Monthly compounding = A = $1432.30
Daily compounding = A = $1433.14
Step-by-step explanation:
The accumulated amounts in terms of compound interest is given by
Where P is the initial amount invested and A is the accumulated amount.
For annual compounding:
i = 0.12
N = 3
For semiannually compounding:
i = 0.12/2 = 0.06
N = 2*3 = 6
For quarerterly compounding:
i = 0.12/4 = 0.03
N = 4*3 = 12
For monthly compounding:
i = 0.12/30 = 0.004
N = 30*3 = 90
For daily compounding:
i = 0.12/365 = 0.0003287
N = 365*3 = 1095