A simple random sample of 60 items resulted in a sample mean of 63. The population standard deviation is 15.

a. Compute the 95% confidence interval for the population mean (to 1 decimal).

b. Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean (to 2 decimals).

a) What is a control chart and what is it used for?

b) What are the steps for constructing a Control Chart?

c) Explain the out of control signals?

A school is interested in whether its student's scores on a standardized test exceed the
national average. The national average is 40 (μ = 40) and the standard deviation is 8 (cr =
8). To determine this, the school officials administer the test to a sample of 16 (n = 16)
students and obtain a mean score of 44 (M = 44). Perform a z-test to determine whether

the students in the school differ significantly from the national average. Perform a two-
tailed test. Compute the obtained z score.

31. An instructor wants to test whether attending class influences how students perform on an
exam. There are 54 students in the class. There are 25 students who attended the class and passed
the exam, 6 students who attended class and failed the exam, 8 students who skipped the class and
passed the exam, 15 students who skipped the class and failed class. Please perform a statistical
test and indicate whether attending class influence the exam performance.

a) Parametric or nonparametric hypotheses?
b) Z distribution, t distribution, chi-square test or hypothesis test of a proportion
c) Please indicate the null hypotheses.
d) Please indicate the alternative hypotheses
e) Please calculate the stand error? (If it is a chi-square test, type NA for this question)
f) If z table will be used, type NA for this question. If t table will be used, indicate the degree of
freedom.
g) Please calculate the statistical value.
h) Hypothesis is supported or no supported, and what is your conclusion?

A yellow light technically means to stop but many people ignore it and drive through. It is thought that men are more aggressive drivers than women and are more prone to go through yellows. Experimenters stood by one traffic light at various times of the day and monitored a random sample of drivers. One experimenter took note of whether the driver stopped or went through the light and the other noted the gender. Here are the results: Drivers Percentage going through yellow Men 71 76% Women 53 65% Run a hypothesis test at the 2% level to check out the conjecture as well as finding a 98% confidence interval for the data?

Statistics has an important role in the analysis of data. However, some claim that the more important role of statistics is in the design stage when one decides how to collect the data. Good design may improve the chances that the eventual inference of the data will lead to a meaningful and trustworthy conclusion. In many situations different types of measurements can be used in order to investigate a scientific problem. Frequently, one may chose between a more accurate but more expensive method of measurement and between a cheaper and less accurate one. For a given budget, choosing to use the first method means that less measurements will be collected. Some say that the quantity of data that is collected is most important. Other say that the quality of the data is more important than the quantity. What is your opinion?

A recent sports game set a record for the number of television viewers. The game had a share of 78​%, meaning that among the television sets in use at the time of the​ game, 78​% were tuned to the game. The sample size is 25,563 households. Use a 0.01 significance level to test the claim that more than 74​%of television sets in use were tuned to the sports game. Identify the null​ hypothesis, alternative​ hypothesis, test​ statistic, P-value, conclusion about the null​hypothesis, and final conclusion that addresses the original claim. Use the​P-value method and the normal distribution as an approximation to the binomial distribution.

1. The test statistic is z=____

2. The P-value=_____

Gru's schemes have a/an 9% chance of succeeding. An agent of the Anti-Villain League obtains access to a simple random sample of 1100 of Gru's upcoming schemes.
Find the probability that...
(Answers should be to four places after the decimal, using chart method, do NOT use the continuity correction):

...between 95 and 101 schemes will succeed:

...less than 8.5% of schemes will succeed:

...more than 9.5% of schemes will succeed:

...between 8.5% and 9.5% of schemes will succeed:

What are some ethical issues that can arise when dealing with data?

The accompanying data table lists the magnitudes of 50 earthquakes measured on the Richter scale. Test the claim that the population of earthquakes has a mean magnitude greater than 1.00. Use a 0.01 significance level. Identify the null​ hypothesis, alternative​ hypothesis, test​ statistic, P-value, and conclusion for the test. Assume this is a simple random sample.

0.690
0.740
0.640
0.390
0.700
2.200
1.980
0.640
1.220
0.200
1.640
1.330
2.950
0.900
1.760
1.010
1.260
0.000
0.650
1.460
1.620
1.830
0.990
1.560
0.390
1.280
0.830
1.320
0.540
1.250
0.920
1.000
0.780
0.790
1.440
1.000
2.240
2.500
1.790
1.250
1.490
0.840
1.420
1.000
1.250
1.420
1.350
0.930
0.400
1.390

1. Identify the test statistic. t=_____

2. The P-value is ______

The Rockwell hardness of a metal is determined by impressing a hardened point into the surface of the metal and then measuring the depth of penetration of the point. Suppose the Rockwell hardness of a particular alloy is normally distributed with mean 71 and standard deviation 3.

a)If a specimen is acceptable only if its hardness is between 70 and 74, what is the probability that a randomly chosen specimen has an acceptable hardness? (Round your answer to four decimal places.)

b) If the acceptable range of hardness is (71 − c, 71 + c), for what value of c would 95% of all specimens have acceptable hardness? (Round your answer to two decimal places.)

c) If the acceptable range is as in part (a) and the hardness of each of ten randomly selected specimens is independently determined, what is the expected number of acceptable specimens among the ten? (Round your answer to two decimal places.)
d)What is the probability that at most eight of ten independently selected specimens have a hardness of less than 73.52? [Hint: Y = the number among the ten specimens with hardness less than 73.52 is a binomial variable; what is p?] (Round your answer to four decimal places.)

Suppose the number of TV's in a household has a binomial distribution with parameters n = 17, and p = 80 %. Find the probability of a household having: A. 12 or 14 TV's B. 12 or fewer TV's C. 15 or more TV's D. Fewer than 14 TV's C. more than 1 Tv's

In november of 1997, austrialians were asked if they thought unemployment would increase. At the time 284 out of a random sample of 631 said that they thought unemployment would increase ("morgan gallup poll,"2013). Estimate the proportion of Austrialians in November 1997 who believed unemployment would increase using a 95% confidence interval.

A) Name of the interval

B) State the random variable and the parameter in words.

C) State and check the assumptions for hypothesis test

D) Find the sample statistics and the confidence interval. Label everything with letters and write the interval as an inequality

E) Statistical Interpretation

F) Real world Interpretation

G) Conclusion:

H) Interpretation:

I need new and unique answers, please. (Use your own words, don't copy and paste), Please Use your keyboard (Don't use handwriting) Thank you..

Course: Introduction to Biostatistics

Please answer the following questions:

Q1. Discuss the tools to measure central tendency.

Q2.a) Discuss parametric and nonparametric test used for hypothesis testing.

b) In a cross sectional study on coronary heart disease (CHD), the smoking and CHD status is summarized below. Use appropriate statistical test to conclude smoking plays any role in CHD.

Using the data in the Excel file Cell Phone Survey, determine if the mean response for Customer Service rating is different for the carriers (consider only AT&T, Verizon, and Sprint) for significance level of 5%.

Gender   Carrier   Type   Usage   Signal strength   Value for the Dollar   Customer Service
M   AT&T   Smart   High   5   4   4
M   AT&T   Smart   High   5   4   2
M   AT&T   Smart   Average   4   4   4
M   AT&T   Smart   Very high   2   3   3
M   AT&T   Smart   Very high   5   5   2
M   AT&T   Smart   Very high   4   3   5
M   AT&T   Smart   Very high   3   4   4
F   AT&T   Smart   Very high   3   2   3
F   AT&T   Smart   Very high   4   3   4
M   AT&T   Smart   Very high   3   3   1
M   Other   Smart   Average   1   2   4
M   Sprint   Smart   Very high   3   5   4
M   Sprint   Smart   Very high   3   5   3
F   Sprint   Smart   Average   2   5   4
F   Sprint   Smart   Average   3   5   4
M   Verizon   Smart   Average   4   3   3
F   Verizon   Smart   Very high   4   3   2
M   Verizon   Smart   Very high   5   5   5
F   Verizon   Smart   Average   3   3   3
M   Verizon   Smart   Very high   4   4   2
F   Verizon   Smart   Very high   4   5   3
M   AT&T   Camera   Average   5   4   5
M   AT&T   Camera   Very high   2   1   3
M   AT&T   Camera   Average   2   4   3
F   AT&T   Camera   Very high   3   3   3
M   AT&T   Camera   Average   5   5   3
F   AT&T   Camera   Average   4   3   3
M   AT&T   Camera   Average   4   2   4
F   AT&T   Camera   Very high   2   4   1
F   AT&T   Camera   Average   2   4   3
M   AT&T   Camera   Average   3   3   4
F   AT&T   Camera   Very high   3   2   3
M   AT&T   Camera   Very high   4   3   3
F   AT&T   Camera   Low   4   2   3
M   Other   Camera   Average   3   3   3
F   Other   Camera   Average   2   3   3
M   Other   Camera   Average   4   3   4
M   Sprint   Camera   Average   3   4   4
F   Verizon   Camera   Very high   3   4   3
F   Verizon   Camera   Very high   4   3   1
M   AT&T   Basic   Average   3   3   3
M   AT&T   Basic   Average   3   3   2
M   AT&T   Basic   Low   3   3   3
M   Other   Basic   Average   3   3   5
M   Other   Basic   Very high   4   3   3
M   Other   Basic   Very high   1   3   4
M   Other   Basic   Low   4   4   2
F   Other   Basic   Average   2   3   3
F   T-mobile   Basic   Low   3   4   4
M   T-mobile   Basic   Average   3   4   3
M   Verizon   Basic   Low   3   3   4
M   Verizon   Basic   Average   4   2   4