Business Statistics Class PROBLEM 2 A company claims that p

Business Statistics Class

PROBLEM 2 :

A company claims that people who are the antioxidant Bera will live at least 10 more years.

n = 16                                   

= 9.5 year

s = 2.5 year

a) Test at a=.05

b) Give the CIE at 95%

PROBLEM 3 :

A company manufactures strollers. A random sample of 25 strollers is taken and the sample mean life is 10.00 years with a standard deviation of 1.50 years. If you were constructing a 90% two-sided confidence interval estimate, the upper limit would be: __________________

PROBLEM 4 :

The Momoland Springs Company claims that at most there are 1 ppm (parts per million) of benzene in their water. Test at a=.05

n=25

= 1.10 ppm

s = .20 ppm

PROBLEM 5 :

Baterry&Gadgets store claims that its batteries have a life of more than 600 hours. The Mall Inspectors test a sample of 20 batteries, and found:

= 595 hours

s = 40 hours

Test at a=.05

Construct a 2-tailed 95% C.I.E of . The upper limit of the confidence interval is 598.72 hours

PROBLEM 6 :

A medical investigation claims that the average number of infections per week at a hospital in Westchester is 16.3. A random sample of 10 weeks had a mean number of 17.7 infections. The sample standard deviation is 1.8. Is there enough evidence to reject the investigator’s claim at a=.05?

n = 10

s = 1.8

= 17.7

Solution

Q2.

Set Up Hypothesis
Null,antioxidant Bera will live at least 10 more years. H0: U>10
Alternate,antioxidant Bera will live less than 10 more years. H1: U<10
Test Statistic
Population Mean(U)=10
Sample X(Mean)=9.5
Standard Deviation(S.D)=2.5
Number (n)=16
we use Test Statistic (t) = x-U/(s.d/Sqrt(n))
to =9.5-10/(2.5/Sqrt(15))
to =-0.8
| to | =0.8
Critical Value
The Value of |t | with n-1 = 15 d.f is 1.753
We got |to| =0.8 & | t | =1.753
Make Decision
Hence Value of |to | < | t | and Here we Do not Reject Ho
P-Value :Left Tail -Ha : ( P < -0.8 ) = 0.2181
Hence Value of P0.05 < 0.2181,Here We Do not Reject Ho

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