Scores of an IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 14. Use the empirical rule to determine the following. (a) What percentage of people has an IQ score between 72 and 128? (b) What percentage of people has an IQ score less than 58 or greater than 142? (c) What percentage of people has an IQ score greater than 128? (a) % (Type an integer or a decimal.) (b) % (Type an integer or a decimal.) (c) % (Type an integer or a decimal.)
Added by Daniel N.
Close
Step 1
The z-score formula is: z = (X - μ) / σ where X is the IQ score, μ is the mean, and σ is the standard deviation. We are given that the mean IQ score is 100 and the standard deviation is 15. For X = 72: z1 = (72 - 100) / 15 = -28 / 15 ≈ -1.87 For X = 127: z2 = Show more…
Show all steps
Your feedback will help us improve your experience
Sri K and 78 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Math 110 Section 003 Homework: Section 1.1 Homework Score: 0 of 1 pt 1.1.21 Find the intercepts. Then graph by using the intercepts, if possible. 3y - x = 3 Use the graphing tool to graph the line. Use the intercepts when drawing the line. If only one intercept exists, use it and another point to draw the line.
Adi S.
An investment pays 10% interest compounded continuously. If money is invested steadily at the rate of $20,000, how much time is required until the value of the investment reaches $200,000? The amount of time required is approximately years. (Type an integer or decimal rounded to the nearest hundredth as needed.)
Sri K.
8.1.19 The test statistic of z = 2.81 is obtained when testing the claim that p ≠ 0.282. a. Identify the hypothesis test as being two-tailed, left-tailed, or right-tailed. b. Find the P-value. c. Using a significance level of Α = 0.01, should we reject H₀ or should we fail to reject H₀? a. This is a two-tailed test. b. P-value = (Round to three decimal places as needed.)
Madhur L.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD