Introduction to Statistics

Posted: August 27th, 2021

Student’s Name

Instructor’s Name

Course

Date

Introduction to Statistics

Question 1: Critical Value of 96%

Question 2: Fast Food Orders

1. Accurate orders= 329

Inaccurate orders= 74

The null and alternative hypotheses are

Test statistics (Z) in null and alternative hypotheses

Accurate orders

Inaccurate orders

Since, the p-value is less than 10%, reject the null hypothesis.

• C. No conclusion can be made because not enough information is given about the confidence interval of restraint B.

Question 3: Programmer

1. With no known information the

 Computers

• Given

Computers

• A. Yes, using the additional survey information from part​(b) dramatically increases the sample size.

Question 4: Confidence Interval

Confidence level= 95%

Significance level=

From the z table,

Therefore, option B is correct

Question 5: Clinical Trial

To get the value of α,the confidence level is deducted from 1

=1.645

=10.6141

Upper limit =

Lower limit =

Therefore,

The drug is ineffective as the  falls within the lower and upper boundary. An effective mean should be the upper limit.

Question 6: Drive-Through Services

For restaurant X, =179.6, n=50, α=63.31

For restaurant Y, =153.2, n=50, α=49.62

At 95% confidence level

For restaurant X,

Upper limit =199.61

Lower limit = 164.59

Therefore,

For restaurant Y

Upper limit =164.97

Lower limit = 141.43

Therefore,

B. the confidence level estimates for the two restaurants do not overlap, so it appears that restaurant Y has a faster mean service time than X.

Question 7: Female Students

At 95% confidence level, the critical value =

Required sample size is approximately 301 students

A. No. because there is no age difference between the population of the statistics students and the general population.