Get Help with Confidence Interval Questions

Recent questions in Confidence intervals

remolatg 2021-01-28

Given $f (x) \cos (2 x)$ and the interval
$[0, 3 \frac{π}{4}]$
approximate the area bounded by the graph of f(x) and the axis on the interval using a left, right, and mid point Riemann sum with $n = 3$

Daniaal Sanchez 2021-01-24

Suppose that the n-th Riemann sum (with n sub-intervals of equal length), for some function f(x) on the intrval [0, 2], is $S_{n} = \frac{2}{n^{2}} \times \sum_{k = 1}^{n} k .$
What is the value of $\int_{0}^{2} f (x) d x ?$

vazelinahS 2021-01-19

Sample of two different models of cars were selected, and the actual speed for each car was determined when the speedometer registered 50 mph. The resulting 95% confidence intervals for mean actual speed were (50.3, 52.7) and (49.8, 50.6) respectively. Assuming that the two sample standard deviations are equal, which confidence interval is based on the larger sample size? Explain your reasoning.

Trent Carpenter 2021-01-15

Use technology to construct the confidence intervals for the population variance $σ^{2}$ and the population standard deviation $σ$ . Assume the sample is taken from a normally distributed population. $c = 0.99, s = 37, n = 20$ The confidence interval for the population variance is (?, ?). The confidence interval for the population standard deviation is (?, ?)

alesterp 2021-01-15

Scott wants to find a $95 %$ confidence interval for the average GPA for Allegany College of Maryland students. He gets the records for 89 student. The results were roughly bell-shaped with a mean of 2.3 and standard deviation of 0.7. Construct a $95 %$ confidence interval in the form: Estimate $\pm$ margin of error.

Mylo O'Moore 2021-01-10

The average zinc concentration recovered from a sample of measurements taken in 36 different locations in a river is found to be 2.6 grams per liter. Find the 95% confidence intervals for the mean zinc concentration in the river. Assume that the population standard deviation is 0.3 gram per liter. $(Z_{0.025} = 1.96, Z_{0.005} = 2.575)$

SchachtN 2021-01-10

A statistics practitioner took a random sample of 43 observations from a population whose standard deviation is 26 and computed the sample mean to be 108. Note: For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits. A. Estimate the population mean with 95% confidence. Confidence Interval = B. Estimate the population mean with 95% confidence, changing the population standard deviation to 58, Confidence Interval = C. Estimate the population mean with 95% confidence, changing the population standard deviation to 8, Confidence Interval =

Nann 2021-01-08

Find all the critical points of the function $f (x) = 5 x^{26} + 12 x^{5} - 60 x^{4} + 56.$ Use the First and/or Second Derivative Test to determine whether each critical point is a local maximum, a local minimum, or neither. You may use either test, or both, but you must show your use of the test(s). You do not need to identify any global extrema.

Khaleesi Herbert 2021-01-08

To find: The confidence interval for the mean population.

Ava-May Nelson 2021-01-07

Consider the region below $f (x) = (6 - x),$ above the x-axis, and between
$x = 0 a n d x = 6.$
Let $x_{i}$ be the midpoint of the i th subinterval.
Approximate the area of the region using six rectangles. Use the midpoints of each subinterval for the heights of the rectangles. The area is approximately how many square units?

necessaryh 2021-01-05

The sample mean and population standard deviation are provided to you. Use this information to construct the $90 % and 95 %$ confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals.
From a random sample of 66 dates, the mean record high daily temperature in a certain city has a mean of ${85.69}^{\circ} F$ . Assume the population standard deviation is ${13.60}^{\circ} F .$
The $90 %$ confidence interval is
The $95 %$ confidence interval is
Which interval is wider?
Interpret the findings.

Isa Trevino 2021-01-05

Use:
$F (x) = 0.2 ((x - 3)^{2}) (x + 1),$ bounded by the x axis, over [-1,2]
Use the limit definition of Riemman Sum to find the earea shaded beneath the curve, round to 3 decimal places.

geduiwelh 2021-01-02

Given $f (x) = x^{2} + 3 x + 8$ , find the average rate of change of $f (x)$ over each of the following pairs of intervals.

Lennie Carroll 2020-12-30

A researcher has gathered information from a random sample of 178 households. For each of the following variables, construct confidence intervals to estimate the population mean. Use the 90% level. a. An average of 2.3 people resides in each household. Standard deviation is 0.35. b. There was an average of 2.1 television sets (s 0.10) and 0.78 telephones (s 0.55) per household. c. The households averaged 6.0 hours of television viewing per day (s 3.0)

tinfoQ 2020-12-29

The presidential election is coming. Five survey companies (A, B, C, D, and E) are doing survey to forecast whether or not the Republican candidate will win the election. Each company randomly selects a sample size between 1000 and 1500 people. All of these five companies interview people over the phone during Tuesday and Wednesday. The interviewee will be asked if he or she is 18 years old or above and U.S. citizen who are registered to vote. If yes, the interviewee will be further asked: will you vote for the Republican candidate? On Thursday morning, these five companies announce their survey sample and results at the same time on the newspapers. The results show that a% (from A), b% (from B), c% (from C), d% (from D), and e% (from E) will support the Republican candidate. The margin of error is plus/minus 3% for all results. Suppose that $c > a > d > e > b$ . When you see these results from the newspapers, can you exactly identify which result(s) is (are) not reliable and not accurate? That is, can you identify which estimation interval(s) does (do) not include the true population proportion? If you can, explain why you can, if no, explain why you cannot and what information you need to identify. Discuss and explain your reasons. You must provide your statistical analysis and reasons.

CheemnCatelvew 2020-12-27

Consider the next 1000 98% Cis for mu that a statistical consultant will obtain for various clients. Suppose the data sets on which the intervals are based are selected independently of one another. How many of these 1000 intervals do you expect to capture the corresponding value of $μ ?$
What is the probability that between 970 and 990 of these intervals conta the corresponding value of Y =the number among the 1000 intervals that contain What kind of random variable is Y) (Use the normal approximation to the binomial distribution)

Reggie 2020-12-25

The International Business Society conducts a series of managerial surveys to detect challenges that international managers encounter and what strategies help them overcome those challenges. A previous study showed that employee retention is the most critical organizational challenge currently confronted by international managers. One strategy that may impact employee retention is a successful employee recognition program. The International Business Society randomly selected 423 small firms and 192 large firms. The study showed that 326 of the 423 small firms have employee retention programs compared to 167 of the 192 large organizations.
a) At the 0.01 level of significance, is there evidence of a significant difference between small firms and large firms concerning the proportion that has employee recognition program?
b) Find the p-value and interpret its meaning?
c) Construct and interpret a $99 %$ confidence interval estimate for the difference between small firms and large firms concerning the proportion of employee recognition program.

snowlovelydayM 2020-12-22

Exploring the role of sample size:
a. Construct 1,000 confidence intervals with $n = 10, p = 0.3$ . What proportion of the $95 %$ confidence intervals included the population proportion, 0.3?
b. Construct 1,000 confidence intervals with $n = 40, p = 0.3$ . What proportion of the $95 %$ confidence intervals included the population proportion, 0.3?
c. Construct 1,000 confidence intervals with $n = 100, p = 0.3$ . What proportion $95 %$ confidence intervals include the proportion of the population, 0.3?

alesterp 2020-12-16

A catalog sales company promises to deliver orders placed on the Internet within three business days.
Follow-up calls to a few randomly selected customers show that a 95% confidence interval for the proportion of all orders that arrive on time is 88
a) What is the meaning of this? Are these findings accurate? Explain.
b) 95% of all random samples of customers will show that 88% of orders arrive on time.
c) 95% of all random samples of customers will show that 82% to 94% of orders arrive on time.
d) We are 95% sure that between 82% and 94% of the orders placed by the sampled customers arrived on time.
e) On 95% of the days, between 82% and 94% of the orders will arrive on time.

Clifland 2020-12-15

The confidence interval for the mean population is $2.5121 < μ < 2.6879 .$

If you are studying engineering, you will encounter at least one confidence intervals equation problem where you will need additional help to get things done or implemented correctly. Take your time to study various confidence interval questions and solutions that have been provided by students like you based on the most popular tasks. Looking for confidence interval exercises and solutions, always explore original instructions first as confidence is a relative subject here that helps to address confidence intervals questions with the elements of probability.

Master Confidence Intervals: Examples, Equations, and Questions