Math 2200

Take Home Quiz

Due Tuesday April 11

th

at the start of class

For each problem: Identify the type of test, write out the null and alternative hypothesis, and include a statement along

1.

Marine engines, particularly those of

large container or cargo ships, are rated to burn fuel based on its viscosity.

The most common fuel is known as 6 oil and should have a kinematic viscosity of 15 mm/s

2

at 100

o

C. Jonny ran

a set of 12 samples of 6 oil from a shore tank and calculated the

mean

viscosity as 14.3 mm/s

2

with a standard

deviation of

1.2

mm/s

2

.

Can Jonny conclude at 99% confidence that the shore tank of 6 oil

is

off spec

? Assume

the distribution is approximately normal.

2.

Gasoline retailers are mandated by the EPA to

have completely transitioned to selling summer

June 1

st

every year. To be considered summer

grade, the Reid Vapor Pressure (RVP)

of the gasoline

can be no

more than 9

psi

.

Enmark

et

is under suspicion of selling winter grade gas past the

June 1

st

investigator pulls

3

0 samples of gas from various Enmark

et

locations and the mean RVP is found to be

9.49

psi.

If the standard deviation of the test method is known to be

0

.

75

psi, can the investigator conclude that they are

sellin

3.

The rumor among gasoline chemists is that

Russia

n oil/gas is very low quality and

Russi

an

boats are rejected

more often than others.

A

s

a

single barge of gasoline can be worth

\$

7

10 million dollar

s

,

ships are

rarely

rejected

(assume no more than 15% of the time)

.

Shamgan was bored one day while waiting for the cargo boat

to arrive and decided to check the old laboratory records.

In the last

3

years a total of

38

gasoline ships

originated from Russia

. Of those

,

7

failed

their chemical testing

and were rejected

.

At a significance level of

95%, can Shamgan safely conclude that

Russian gas is more likely to

be rejected than

other

gas

?