statsHelp

i have 2 simple questions in stats and i have answers as well , all i need is step by step solution in word file , please reply if you can complete in 1 hr 

1) (

2

0points) The time needed to complete a statistics test at national level is normally distributed with a mean of 120 minutes (2 hours) and standard deviation of 21 minutes.

a. (6pt) What is the probability of completing a stats test in one hour or less (60 min)? Write down your answer for full credit.

b. (7pt) What is the probability that a student complete a test in more than 2 hours (120) but less than two hours and 30 minutes (150min)? Write down your conclusion for full credit.

c. (7pt) What is the probability that a student completes a stats test in more than 2 hours?

Write your conclusion for full credit.

2) (30pt) Wall Street traders are an

x

iously waiting for the federal government’s release of the February numbers for nonfarm payrolls. Last year month of February showed an average of 250,000 new jobs with a standard deviation of 60,000. A sample of 100 nonfarm payrolls taken earlier in the week shows a sample mean of 243,000. Financial analysts often call such a sample mean the “whisper number”. Conduct a hypothesis test to determine whether the whisper number justifies a conclusion of a statistically significant change in the number of new jobs with respect to last year. Allow for 5% error in the test. The hypothesis setting for the test follows.

H0 : µ = 250,000

Ha : µ ≠ 250,000

a. (15pt) Conduct hypothesis test using a
critical-value
approach.

b. (6pt) Conduct a hypothesis test using a
p
-value
approach with 95% confidence.

c. (4pt)Draw a graph showing the critical value test.

x

x

d. (5pt)According to the statistical analysis you have performed above, do you think the whisper number does justify a conclusion of a statistically significant change in the number of new jobs? WHY?

� EMBED Equation.3 ���

Acceptance area

Reject null

Reject null

Z – 1.66 -1.96 0 1.96 1.66

2

_1293879672.unknown

2

>1

d

>

a b

le>

Mean 120 SD 21 a
X 60 Probability 0.0021 The probability of less than 60 in a normal distribution

c

urve is 0.0021 b
X 120

150 Probability

0.4234362745 The probability of between 120 and 150 in a normal distribution curve is 0.4234 c
X 120
Probability

0.5 The Probability of more than 120 is 0.5

2

X

a

b

c

d

new jobs	250000
sd	60000
sample	100
243000
Critical Value	348691.217617088
Reject Null hypothesis as the observed mean is less than the critical value
P value	0.0000017189
Reject null hypothesis as the probability is less than 0.05
Z value	-4.6427600841
It has changed according to the above analysis.