## Which Python method in statsmodels module is used to perform a hypothesis test for a population proportion?

`proportions_ztest(counts, nobs, value)`

is used to perform hypothesis test for a population proportion.

`proportions_ztest`

can be imported from the `statsmodels.stats.proportion`

library using the following command:

```
from statsmodels.stats.proportion import proportions_ztest
proportions_ztest(counts, nobs, value)
```

**Output**

`(1.134556764847714, .53258567853367)`

`proportions_ztest`

returns the z-score and the two-tailed p-value for the z-test.

## Which Python scipy.stats submodule is used to calculate a confidence interval based on the Student’s t-distribution?

Form the `scipy.stats`

submodule, `st.t.intervals`

is used to calculate a confidence interval for a variable based on the t-distribution

**Example**

```
import scipy.stats as st
print(st.t.interval(confindenece_level, degrees_of_freedon, mean, standard_error))
```

**Output**

`(425.85746575867464, 432.98768674649464)`

`st.t.intervals`

returns the confidence interval for the variable based on the t-distribution

## What are the inputs to proportions_ztest method?

`proportions_ztest`

can be imported from the `statsmodels.stats.proportion`

library using the following command:

```
from statsmodels.stats.proportion import proportions_ztest
proportions_ztest(counts, nobs, value)
```

The inputs for `proportions_ztest`

are `count`

, `nobs`

, and `value`

## Which Python method from the scipy.stats submodule is used to calculate a confidence interval based on the Normal Distribution?

`st.norm.interval`

is the method used from `scipy.stats`

submodule to calculate a confidence interval based on the Normal Distribution

**Example**

```
import scipy.stats as st
print(st.norm.interval(confidence_level, sample_mean, standard_error))
```

**Output**

`(425.85746575867464, 432.98768674649464)`

`st.norm.intervals`

returns the confidence interval for the variable based on the a normal distribution.

## What are the inputs to ztest method in Python?

The inputs to `ztest`

are `dataframe`

and `population_mean`

**Example**

```
from statsmodels.stats.weightstats import ztest
import pandas as pd
dataframe = pd.read_csv(some_url)
print(ztest(x1 = dataframe, value = pupulation_mean))
```

`ztest`

returns the z-score and the t-tailed p-value

## Which Python module is used to create confidence intervals

The Pythong `scipy`

is used to create confidence intervals.

**Example**

```
import scipy.stats as st
print(st.norm.interval(confidence_level, sample_mean, standard_error))
print(st.t.interval(confindenece_level, degrees_of_freedon, mean, standard_error))
```

`st.norm.intervals`

returns the confidence interval for the variable based on the a normal distribution.

`st.t.intervals`

returns the confidence interval for the variable based on the t-distribution

## Which Python method is used to perform hypothesis testing for a population mean when the population standard deviation is unknown

`ttest_1samp(dataframe, null hypothesis value)`

is used to perform hypothesis testing for a population mean when the population standard deviation is unknown

**Example**

```
import scipy.stats as st
import pandas as pd
datafram = pd.read_csv(some_url)
print(st.stats.ttest_1samp(dataframe, hypothesized_population_mean))
```

`ttest_1samp`

returns the t-statistic and two-tailed p-value.

## Which Python method is used to perform hypothesis testing for a population mean when the population standard deviation is known

`ztest(dataframe, null_hypothesis_value)`

is used to perform hypothesis testing for a population mean when the population standard deviation is known

**Example**

```
import statsmodels.stats.weightstats import ztest
import pandas as pd
datafram = pd.read_csv(some_url)
print(ztest(dataframe, hypothesized_population_mean))
```

`ztest`

returns the z-score and the two-tailed p-value.

## What are the inputs to ttest_ind method in the scipy module?

`st.ttest_ind(dataFrame['One'], dataFrame['Two'])`

takes two DataFrame columns of equal length as input.

`st.ttest_ind(dataFrame['One'], dataFrame['Two'])`

returns the calculated t-statistic and the p-value.

## Which Python method is used to perform a hypothesis test for the difference in two population proportions

The `proportions_ztest()`

is imported from the `statsmodels.stats.proportion`

submodule and is used to perform a hypothesis test for the difference in two population proportions

**Example**

```
from statsmodels.stats.proportion import proportions_ztest
proportions_ztest(array_of_samples_meating_condition, array_of_number_of_samples_in_each_group)
```

The function returns the z-score and the two-tailed p-value

## Which Python method is used to perform an unpaired t-test for the difference in two population means?

`st.ttest_ind(x, y)`

is used to perform an unpaired t-test for the difference in two population means

**Example**

```
import scipy.stats as st
import pandas as pd
dataframe = pd.read_csv(some_url)
st.ttest_ind(dataframe['One'], dataframe['Two'])
```