Weekly household expenditure in a country is normally distributed with a mean $1200 and standard deviation of $300.1. What is the probability that the weekly expenditure of a randomly selected household will be more than $1600?
Question
Weekly household expenditure in a country is normally distributed with a mean 300.1. What is the probability that the weekly expenditure of a randomly selected household will be more than $1600?
Solution
To solve this problem, we need to use the concept of Z-score in statistics. The Z-score is a measure of how many standard deviations an element is from the mean.
Step 1: Identify the mean, standard deviation, and the value for which we need to find the probability. In this case, mean (μ) = 300.1, and the value (X) = $1600.
Step 2: Calculate the Z-score. The formula for Z-score is:
Z = (X - μ) / σ
Substituting the given values into the formula, we get:
Z = (1200) / $300.1 = 1.33 (rounded to two decimal places)
Step 3: Look up this Z-score in the Z-table to find the probability. The Z-table tells us the probability to the left of our Z-score. But we want the probability that the expenditure is more than $1600, so we want the area to the right of our Z-score.
The Z-table tells us that the probability to the left of Z = 1.33 is 0.9082. Therefore, the probability to the right is 1 - 0.9082 = 0.0918.
So, the probability that the weekly expenditure of a randomly selected household will be more than $1600 is 0.0918 or 9.18%.
Similar Questions
Suppose that, on average, electricians earn approximately µ = $54,000 per year in the United States. Assume that the distribution for electricians’ yearly earnings is normally distributed and that the standard deviation is σ = $12,000. What is the probability that the average salary of four randomly selected electricians exceeds $60,000?Multiple Choice0.15870.69150.30850.8413
Jackson is a builder. He finds that the weekly operating cost varies from week to week. Weekly earnings are normally distributed with a mean of $1,200. What is the probability that the weekly earnings of Jackson are below $1,200?Group of answer choices0.25Cannot be answered based on the information.0.50.75
Electricity bills: According to a government energy agency, the mean monthly household electricity bill in the United States in 2011 was $109.77. Assume the amounts are normally distributed with standard deviation $22.00. Use the TI-84 Plus calculator to answer the following.(a) What proportion of bills are greater than $137?(b) What proportion of bills are between $85 and $148?(c) What is the probability that a randomly selected household had a monthly bill less than $119?Round the answers to at least four decimal places.Part 1 of 3The proportion of bills that are greater than $137 is .Part 2 of 3The proportion of bills that are between $85 and $148 is.Part 3 of 3The probability that a randomly selected household had a monthly bill less than $119 is .CheckSave For LaterSubmit Assignment
Monthly Mortgage Payments The average monthly mortgage payment including principal and interest is $982 in the United States. Assume that the standard deviation is approximately $180 and the mortgage payments are approximately normally distributed. Find these probabilities of the monthly payment selected randomly. Enter the final answers as decimals rounded to at least four places. Use The Standard Normal Distribution Table. Round intermediate z-value calculations to two decimal places
Assume that the random variable X is normally distributed with mean μ = 120 and standard deviation σ = 13. Find P(110 < X < 145).
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.