1.Consider the two way table below

Trainee Upper Management

Young 995 1

Old 5 99

Total 1000 100

What is probability the person is old if you assume the Hypothesis the person is a trainee is true?

2.Suppose you have a list of observations and you find the list of z scores by using the formula

z score = (raw - mean of list) /(stdev of list)

And one of the observations has a z score of -19.1

a.

None of the options is correct

b.

Very few or none of the other observationson the list will have a z scoremore than -19.1 so the percentile of the observation with a zscore of -19.1 is the 100th percentile or close to the 100th percentile

c.

The observation with a z score of -19.1 is the median (the 50th percentile)

d.

Very few or none of the other observationson the list willhave a z scoreless than-19.1 so the percentile of the observation with a zscore of -19.1 is the 0th percentile or close to the 0th percentile

3.If you have a list of observations and you find the list of z scores by using the formula

z score = (raw - mean of list) /(stdev of list)

and one of the observations has a z score of 10.9

a.

Very few or none of the other observationson the list will have a z scoremore than 10.9, so the observation with a zscore or 10.9 is the 100th percentile or is close to the 100th percentile

b.

The observationwith a z score of 10.9 is the median (the 50th percentile)

c.

None of the options is correct

d.

Very few or none of the other observationson the list willhave a z scoreless than 10.9. so the observation with a zscore or 10.9 will be close to the 0th percentile

4.Which of the assumptions given below is one of the assumptions required for the test of proportion and is also one of the required assumptions for the test of the mean.

Select the BEST answer

Select one:

a.

Equal variance

b.

All of the other options are correct

c.

A positive slope

d.

Independent observations

5.Perform the Hypothesis test

Suppose a sample of 22 chocolate bars has a mean weight of 1001.4with standard deviation 36. Testthe claim the mean weight is above 1001usea 5% level of significance

• the test stat is 95.05
• the test stat is 0.05
• the test stat is -62.95
• H0: p=1001H0: p more than 1001
• The test stat is notabove the critical value from the table so do notreject H0 there is not strong evidence the mean is above 1001
• The test stat is not above the critical value from the table so reject H0 there is strong evidence the mean is above 1001.40
• H0: =1001H1: more than 1001

6.Suppose a student is testing the claim the proportion is below51 % and correctly finds the test stat is 0.35 select all the other options the student needs to choose to get full marks ,

assume the significance level is 5%

a.

H0: p=0.51 H1:p lessthan 0.51

b.

Reject H0 there is strong evidence the population proportion is above 0.51

c.

Do not Reject H0 there is not strong evidence the population proportion is below0.51

d.

H0: p=0.51 H1:p greater than 0.51

7.Suppose asample of 100 customers spends an average of $110 with standard deviation of

$31. Find a 95% confidence interval for the mean if 95% of sample means are within 1.984 estimated standard errors of the population mean when the sample size is 100.

select the closest answer

click here if you want a guide

a.

between 103.85 and 116.15

b.

31

c.

between 106.90 and 113.10

d.

110

e.

between 334.85 and 347.15

8.Find the 95% confidence interval for proportion of females using the information below if 95% ofsample proportions are within 1.96 standard errors of the population proportion.

Suppose you have a sample of 1600 people that buy an Xbox butthere are only306 are female

a.

between 0.17 and 0.21

b.

between 0.11 and 0.27

c.

306.00

d.

between -0.02 and 0.02

e.

between -0.79 and 1.17

9.Find the sample standard deviation of the sample

0.8 ,3.4

Hint: that the sample mean is 2.1

10.Find the standard deviation of the gambling game with probability distribution

profit X -1 3.2

probabilityP(X) 0.8 0.2

Hint the population mean is -0.16

11.Consider the probability distributionbelow

x probability p(x)

0 0.8

48 0.2

12.Suppose 37000 high school students test, so the test mark is a quantitative variable X. Ifmark of 20 is the 2.3th percentile . How many high school students get a mark below 20?

13.Suppose an estimate is normally distributed with mean 2007.3 and standard deviation 100

so 84.13% of estimates are less than 2107.3, what is the 84.13th percentile of estimates ?

Note the answer to this question is VERY easy if you have bothered to learn what a percentile is

14Suppose you have a dataset with 2 quantitative variables X and Y

and you find the

the sample mean of X is 200 with stdev 10

The sample mean of Y is 3000 with stdev 100

and the correlation coefficient r= 0.9

so you can make the following predictions

Future value of Xzscore of Xpredicted value of Y80-2282090-12910100030001101309012023180

What would a plot of these points look like

Select one:

a.

option 2

b.

option 1

Select one: Oa. 3500 3000 2500 2000 1500 1000 500 80 90 100 110 120 option 2 O b. predicted value of Y 3180 3090 Y 3000 2910 2820. 80 90 100 110 120 option 1 X Clear my choice