Question

Which below are types of estimation in statistics?

i. Point Estimation
ii. Interval Estimation
iii. Suspended Estimation

i only

Both i and ii

Both i and iii

Both ii and iii

Answer 1

Suspended Estimation is not a valid statistical procedure. Sounds like "suspended animation" to through you off!

Answer 2

so b?

Answer 3

yep

Answer 4

http://en.wikipedia.org/wiki/Point_estimation
http://en.wikipedia.org/wiki/Interval_estimation

Answer 5

Soda Tak claims that Diet Tak has 40mg of sodium per can. You work for a consumer organization that tests such claims. You take a random sample of 60 cans and find that the mean amount of sodium in the sample is 42.4mg. The standard deviation in all cans is 7.2mg. You suspect that there is more than 40mg of sodium per can. Find the z-score.

0.2

2.582

2.727

5.143

Answer 6

i already worked this ut with @agent0smith we both said it was b but i wanted to see if you had the same answer

Answer 7

I said it was 1/3, i said it wasn't an option

Answer 8

same 0.33

Answer 9

actually so wouldnt it be 0.2?

Answer 10

-1/3 actually

Answer 11

I dont understand so what would be a logical answer?

Answer 12

none unless the sample mean has something to do with it

Answer 13

@ybarrap ?

Answer 14

what would you say?

Answer 15

$$
Z = \frac{\bar{X}-\operatorname{E}[X]}{\sigma(X)/\sqrt{n}}=\cfrac{(42.4-40)}{7.2/\sqrt{60} }=2.36682...
$$
http://www.wolframalpha.com/input/?i=%2842.2-40%29%2F%287.2%2Fsqrt%2860%29%29

http://en.wikipedia.org/wiki/Z_score#Standardizing_in_mathematical_statistics

None of the options match

Answer 16

i guess we can go b?

Answer 17

Technically, they are all wrong. Question wasn't asking for the closest answer

Answer 18

this is pretty easy i think

Answer 19

The table above gives data about Magic Sugar cereal. Which is the value used for chi-squared cdf?

(1.5179,999,3)

(0.4882,999,4)

(0.6287,999,4)

(0.4882,999,3)

Answer 20

yes, VERY easy

Answer 21

just calculations

Answer 22

i would say it is b?

Answer 23

did you do the calculations?

Answer 24

im doing them now

Answer 25

http://www.wolframalpha.com/input/?i=%2810-11%29^2%2F11+%2B+%2811-10.5%29^2%2F10.5+%2B+%2812-9%29^2%2F9+%2B+%2813-15.5%29^2%2F15.5

Answer 26

A. :)

Answer 27

:)

Answer 28

You test calories for a food item. The brand name has a mean of 158.706 and a sample standard deviation =25.236, when seventeen are tested. The generic item has a mean of 122.471 and a sample standard deviation =25.183, when seventeen are tested. Which is a confidence interval of 95%?

17.21 to 55.26

17.79 to 54.67

18.622 to 53.848

18.12 to 54.35

Answer 29

maybe c?

Answer 30

i dont know my calculations are different

Answer 31

These number are too small. The averages are 122.471 and 158.706, which were given. So, the 95% interval should include one of these. No option works.

Answer 32

none of the options are correct?

Answer 33

Obviously! The intervals should include the average!

Answer 34

okie dokie!

Answer 35

Hotdog toppings in a box are mixed in a large tray near the customer service area. The packets include 13 ketchup, 11 salt, 9 honey, 14 mustard, 10 BBQ, and 11 relish. When completing a goodness of fit, what is the degree(s) of freedom?

1

3

5

6

Answer 36

It should be 5 because once you compute the average and you have 5 terms, you can easily compute the 6th term. So their is NO degree of freedom for the 5th term once you have that average.

Answer 37

C?

Answer 38

Yes

Answer 39

Which statement below is true about a 95% confidence interval where the poputation mean is contained within the interval of 3.2 to 3.8?

The width of this interval is 3.8.

The sample mean is 1.19.

The margin of error is 0.3.

The CI of 95% uses 1.960.

Answer 40

@ybarrap

Answer 41

3.8-3.2 = .6 This is the full length of the interval. Half of this is the distance from the mean, so margin of error is half of this.

Answer 42

C!

Answer 43

what is half of .6 ?

Answer 44

haha oh shut up you ;)

Answer 45

:)

Answer 46

The table above gives data about Magic Marshmallows cereal. Which value belongs in the bottom of the horseshoes column?

0.0238

0.0909

0.111

1

Answer 47

this is the same table from before but different question

Answer 48

$$
\cfrac{(O-E)^2}{E}=\cfrac{(12-9)^2}{9}
$$

Whatever this is...

Answer 49

D!

Answer 50

Find the expected frequency for cell (space) #2 of the contingency table.

38.19

42.75

44.77

46.17

Answer 51

help!

Answer 52

383/9 = 42.6

Answer 53

B!

Answer 54

Should be exact, none match

Answer 55

There is a new treatment for smokers to stop smoking. In an experiment, 85% of 300 smokers quit after 10 days of the treatment. What is the reasonable range for the success rate p of our new treatment? Which is the 95% confidence interval?

0.755 to 0.845

0.8096 to 0.8904

0.8048 to 0.8952

0.749 to 0.851

Answer 56

C?

Answer 57

Look for an interval where .85 is right smack in the middle

Answer 58

okie dokie

Answer 59

b or c?

Answer 60

Take the average of each number and get the one that is closest to .85

Answer 61

how do i do that?

Answer 62

http://www.wolframalpha.com/input/?i=%28.8096+%2B.8904%29%2F2

Answer 63

B!

Answer 64

rihgt?

Answer 65

the 3rd one works also, we need to find the 95% for proportion

Answer 66

darnit you're right i checked wulf and i dont know what to choose from b or c :(

Answer 67

help!

Answer 68

80.96% to 89.04%

Answer 69

https://www.mccallum-layton.co.uk/tools/statistic-calculators/confidence-interval-for-proportions-calculator/

Answer 70

so b would be a final answer!

Answer 71

yep

Answer 72

In a survey done about voting and gender, it was found that 75 of 200 males voted in a recent election while 124 of 220 females voted. What is the difference between the proportion of females who vote and the proportion of males who vote? That is, which is a 95% confidence interval for the difference?

0.225 to 0.402

0.095 to 0.282

0.044 to 0.233

0.050 to 0.147

Answer 73

brb

Answer 74

alrighty @ybarrap :) tel me when your're back!

Answer 75

back

Answer 76

^ i need help on the question above

Answer 77

@ybarrap

Answer 78

what would you sayit would be ?

Answer 79

difference in proportion is is 0.18863636363636363636363636363636363636363636363636...

So 95% conf interval is .0932 to .2792

http://vassarstats.net/prop2_ind.html

Answer 80

B! it really doesnt matter it doesnt have to be exact. retricelong as its arond that number

Answer 81

so yeah b

Answer 82

Find the 99% confidence interval for the population mean when the population standard deviation is 3. The sample mean is 6. We assume that the population has a normal distribution. Ten items are taken in the sample.

3.52 to 8.48

2.74 to 9.26

3.56 to 8.44

4.14 to 7.86

Answer 83

http://www.wolframalpha.com/input/?i=confidence+interval+for+mean&f1=0.99&f=ZInterval.c_0.99&f2=10&f=ZInterval.n_10&f3=3&f=ZInterval.sigma_3&f4=6&f=ZInterval.xbar_6

Answer 84

C!

Answer 85

The number of candy pieces in a bag is calculated for a sample of 40 bags of a particular manufacture. Based on this data, the sample mean is 25.30 pieces. The population standard deviation is to be 3.2 (remember this is the unrealistic part, we would not really know this).

Which below is a 95% confidence interval for the mean number of pieces of candy per bag?
Note: 95% of all possible confidence intervals for a sample size of 30 will contain the population mean. Use 1.960 for a 95% CI and 2.576 for a 99% CI.

(23.76,26.84)

(24.31,26.29)

(20.17,20.57)

(23.99,26.60)

Answer 86

http://www.wolframalpha.com/input/?i=confidence+interval+for+mean&f1=0.95&f=ZInterval.c_0.95&f2=40&f=ZInterval.n_40&f3=3.2&f=ZInterval.sigma_3.2&f4=25.3&f=ZInterval.xbar_25.3

Answer 87

Which below is a reasonable rule of check in order to use t-procedures when the sample size is 15 < n < 40?

The sample distribution should be pretty normal. There should not be any outliers and very little skewness.

There should not be any large outliers and there should not be extreme skewness.

The sample size is large enough to use t-procedures regardless.

There is no reasonable rule for checking a sample size of this size.

Answer 88

The only one that makes sense to me is The sample size is large enough to use t-procedures regardless.

Answer 89

I can tell you why, but that would be a lecture

Answer 90

Too long! haha

Answer 91

Your younger brother is getting stickers from a vending machine at the local supermarket. What is the proportion that a sticker has the message 'Girls Rule’? Let’s take a sample to try to determine this. let’s say the vending machine stickers represent a random sample of size n from the population of these stickers.

In the machine you count 6 of them with the message 'Girls Rule' among the 42 total stickers. Which is 95% confidence interval when dealing with proportions?

0.025 to 0.225

0.031 to 0.235

0.037 to 0.249

0.041 to 0.213

Answer 92

3.71% to 24.89%
http://www.wolframalpha.com/input/?i=6%2F42

https://www.mccallum-layton.co.uk/tools/statistic-calculators/confidence-interval-for-proportions-calculator/

wulff

Answer 93

C!