NT |
-3.23% |
16.66% |
-0.72% |
2.16% |
13.38% |
10.56% |
-3.93% |
5.85% |
-2.76% |
5.11% |
1.08% |
3.74% |
2.06% |
-4.55% |
17.46% |
-0.45% |
-1.81% |
-11.98% |
-2.09% |
12.84% |
-2.37% |
9.71% |
-1.77% |
5.86% |
6.81% |
11.55% |
7.14% |
-2.67% |
8.90% |
0.31% |
-1.57% |
6.69% |
4.18% |
3.15% |
3.89% |
2.94% |
-6.75% |
-9.47% |
-4.00% |
-5.77% |
-5.10% |
-2.51% |
-6.62% |
22.05% |
7.42% |
3.30% |
0.58% |
1.16% |
-0.72% |
2.16% |
13.38% |
3.74% |
2.06% |
-4.55% |
6.81% |
11.55% |
7.14% |
-6.75% |
7.42% |
-9.47% |
S&P 500 |
2.40% |
5.20% |
4.00% |
-0.50% |
9.00% |
1.90% |
-0.40% |
-2.30% |
2.10% |
2.40% |
-6.70% |
1.30% |
2.60% |
-2.50% |
9.80% |
-0.70% |
-0.30% |
-9.00% |
-4.90% |
-0.40% |
6.40% |
2.70% |
4.40% |
7.20% |
2.40% |
0.30% |
4.30% |
-4.60% |
4.70% |
2.40% |
-1.60% |
1.30% |
-4.00% |
11.40% |
-1.90% |
1.30% |
-2.00% |
2.90% |
0.50% |
-1.50% |
4.00% |
-2.00% |
1.20% |
0.40% |
3.40% |
1.30% |
0.70% |
1.40% |
4.00% |
-0.50% |
9.00% |
1.30% |
2.60% |
-2.50% |
2.40% |
0.30% |
4.30% |
-2.00% |
3.40% |
2.90% |
In: Statistics and Probability
Let x be a random variable that represents the level of glucose in the blood (milligrams per deciliter of blood) after a 12 hour fast. Assume that for people under 50 years old, x has a distribution that is approximately normal, with mean μ = 72 and estimated standard deviation σ = 41. A test result x < 40 is an indication of severe excess insulin, and medication is usually prescribed.
(a) What is the probability that, on a single test, x
< 40? (Round your answer to four decimal places.)
(b) Suppose a doctor uses the average x for two tests
taken about a week apart. What can we say about the probability
distribution of x? Hint: See Theorem 6.1.
The probability distribution of x is not normal.The probability distribution of x is approximately normal with μx = 72 and σx = 20.50. The probability distribution of x is approximately normal with μx = 72 and σx = 28.99.The probability distribution of x is approximately normal with μx = 72 and σx = 41.
What is the probability that x < 40? (Round your answer
to four decimal places.)
(c) Repeat part (b) for n = 3 tests taken a week apart.
(Round your answer to four decimal places.)
(d) Repeat part (b) for n = 5 tests taken a week apart.
(Round your answer to four decimal places.)
(e) Compare your answers to parts (a), (b), (c), and (d). Did the
probabilities decrease as n increased?
YesNo
In: Statistics and Probability
An IQ test scoring is designed to have mean of 100 and a standard deviation of 15. The scores are known to be normally distributed. A principal at a private school wants to investigate whether the average IQ of the students at her school is statistically different from the designed mean. She randomly samples from the school and has 15 students take the IQ test. The average test score of the sample is 95 and the sample standard deviation is 2. Use α = .10
1. Follow the 7 steps for hypothesis testing to solve this problem using the critical region method.
2. Calculate the p value.
3. Calculate the 90% confidence interval. Look to see if the hypothesized mean is in confidence intervals.
4. Do you come to the same conclusion using critical region, p value and confidence intervals?
In: Statistics and Probability
In: Statistics and Probability
Visit the NASDAQ historical prices weblink. First, set the date range to be for exactly 1 year ending on the Monday that this course started. For example, if the current term started on April 1, 2018, then use April 1, 2017 – March 31, 2018. (Do NOT use these dates. Use the dates that match up with the current term.) Do this by clicking on the blue dates after “Time Period”. Next, click the “Apply” button. Next, click the link on the right side of the page that says “Download Data” to save the file to your computer.
This project will only use the Close values. Assume that the closing prices of the stock form a normally distributed data set. This means that you need to use Excel to find the mean and standard deviation. Then, use those numbers and the methods you learned in sections 6.1-6.3 of the course textbook for normal distributions to answer the questions. Do NOT count the number of data points.
Complete this portion of the assignment within a single Excel file. Show your work or explain how you obtained each of your answers. Answers with no work and no explanation will receive no credit.
b) What the mean and Standard Deviation (SD) of the Close column in your data set?
c) If a person bought 1 share of Google stock within the last year, what is the probability that the stock on that day closed at less than the mean for that year? Hint: You do not want to calculate the mean to answer this one. The probability would be the same for any normal distribution.
In: Statistics and Probability
Test the hypothesis using the P-value approach. Be sure to verify the requirements of the test. H0: p=0.91 versus H1: p≠0.9
In: Statistics and Probability
Thirty-one small communities in Connecticut (population near 10,000 each) gave an average of x = 138.5 reported cases of larceny per year. Assume that σ is known to be 44.5 cases per year.
(a) Find a 90% confidence interval for the population mean annual number of reported larceny cases in such communities. What is the margin of error? (Round your answers to one decimal place.)
lower limit | |
upper limit | |
margin of error |
(b) Find a 95% confidence interval for the population mean annual
number of reported larceny cases in such communities. What is the
margin of error? (Round your answers to one decimal place.)
lower limit | |
upper limit | |
margin of error |
(c) Find a 99% confidence interval for the population mean annual
number of reported larceny cases in such communities. What is the
margin of error? (Round your answers to one decimal place.)
lower limit | |
upper limit | |
margin of error |
(d) Compare the margins of error for parts (a) through (c). As the
confidence levels increase, do the margins of error increase?
As the confidence level increases, the margin of error increases.As the confidence level increases, the margin of error remains the same. As the confidence level increases, the margin of error decreases.
(e) Compare the lengths of the confidence intervals for parts (a)
through (c). As the confidence levels increase, do the confidence
intervals increase in length?
As the confidence level increases, the confidence interval decreases in length.As the confidence level increases, the confidence interval increases in length. As the confidence level increases, the confidence interval remains the same length.
In: Statistics and Probability
1. In a random sample of male and female New York street performers between the ages of 22-35 you know that:
The probability a man is a mime is 0.30.
the probability a woman is a spray paint artist is 0.165
The probability a man is a break dancer; given that he’s a mime is 0.250.
The probability a woman is a faux statue is 0.550.
The probability a woman is a faux statue, given that she’s a spray paint artist is .065.
Compute the following probabilities: (6 points: 2 points for each problem)
a.P(woman is a spray paint artist and a faux statue)
b.P (woman is a spray paint
artist or a faux statue)
c.P (man is a mime and a break dancer)
In: Statistics and Probability
you draw a single card from a standard 52-card deck. find the probability of each event. simplify the probability ratio or write in decimal form. a) ace or a nine b) not a king c) club or a face card d) spade or a heart e) neither a diamond nor a 7
In: Statistics and Probability
Describes at least 5 differences between the interpretation of results from an efficacy study and an effectiveness study (Minimum 300 words)
In: Statistics and Probability
The major stock market indexes had strong results in 2014. The mean one-year return for stocks in the S&P 500, a group of 500 very large companies was +11.4%. The mean one year return for the NASDAQ, a group of 3200 small and medium-sized companies was +13.4%. Historically, the one-year returns are approximately normal, the standard deviation in the S&P 500 is approximately 20% and the standard deviation in NASDAQ is approximately 30%.
Please explain how you get the answer to x (or Z) step by step
In: Statistics and Probability
The following example comes from Statistics: Concepts and Controversies, by David Moore and William Notz.
Find an example of one of the following:
1. Leaving out essential information
2. Lack of consistency
3. Implausible numbers
4. Faulty Arithmetic
Explain in detail the statistical shortcomings of your example.
In: Statistics and Probability
Please give an example of when using the probability
an event will occur is important to decision making.
Why?
In: Statistics and Probability
Suppose x has a distribution with μ = 23 and σ = 18.
(a) If a random sample of size n = 42 is drawn, find μx, σx and P(23 ≤ x ≤ 25). (Round σx to two decimal places and the probability to four decimal places.)
μx = |
σx = |
P(23 ≤ x ≤ 25) = |
(b) If a random sample of size n = 63 is drawn, find
μx, σx
and P(23 ≤ x ≤ 25). (Round
σx to two decimal places and the
probability to four decimal places.)
μx = |
σx = |
P(23 ≤ x ≤ 25) = |
(c) Why should you expect the probability of part (b) to be higher
than that of part (a)? (Hint: Consider the standard
deviations in parts (a) and (b).)
The standard deviation of part (b) is ---Select---
smaller than larger than the same as part (a) because of
the ---Select--- larger smaller same sample size.
Therefore, the distribution about μx
is ---Select--- wider narrower the same .
In: Statistics and Probability
Assume that a sample is used to estimate a population mean μμ. Find the 99.5% confidence interval for a sample of size 642 with a mean of 22.2 and a standard deviation of 9.3. Enter your answers accurate to four decimal places.
Confidence Interval = ( , )
You measure 29 textbooks' weights, and find they have a mean
weight of 47 ounces. Assume the population standard deviation is
10.8 ounces. Based on this, construct a 99.5% confidence interval
for the true population mean textbook weight.
Keep 4 decimal places of accuracy in any calculations you do.
Report your answers to four decimal places.
Confidence Interval = ( , )
In: Statistics and Probability