if You flip an coin 200 times about how many times would you expect the coin to labd on tails what is the probality

A researcher wants to determine whether the number of minutes adults spend online per day is related to gender. A random sample

suter [353]

Answer:

The expected frequency for the cell E2,2 is = 33

Step-by-step explanation:

The given data is

Gender | 0-30| 30-60| 60-90| 90+ Totals

Male | 23 | 35 | 76 | 46 180

Female | 31 | 42 | 46 | 16 135

Totals 54 77 122 62 315

The expected frequency for the cell E2,2 is :

Expected for the (30-60 box for females) = Total of (30-6)/ (total )* females

= ( 77/315)135= 33

Here p= 77/315 and n= 135

therefor X= pn = 33

χ²= (33-42)²/33= 2.455 ( for the single value of E2,2=33)

Expected for the (30-60 box for males) = Total of (30-6)/ (total )* males

= ( 77/315)180= 44

χ²= (44-42)²/44= 0.09

The critical region is χ² (0.05) 3 ≥ χ²= 11.34

Let the null and alternate hypothesis be

H0:the number of minutes spent online per day is not related to gender

against

Ha: the number of minutes spent online per day is related to gender

The single value of χ² for E2,2 = 2.45 is less than the critical value of 11.34.

6 0

2 years ago

Fowle Marketing Research Inc., bases charges to a client on the assumption that telephone surveys can be completed in a mean tim

sergejj [24]

Answer:

a) Null hypothesis: $\mu \leq 15$

Alternative hypothesis: $\mu > 15$

b) $t=\frac{17-15}{\frac{4}{\sqrt{35}}}=2.958$

c) $p_v =P(t_{34}>2.958)=0.0028$

d) If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 15 at 1% of signficance.

Step-by-step explanation:

Data given and notation

The sample mean is given by:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And the sample deviation is:

$s = \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X=17$ represent the sample mean

$s=4$ represent the sample standard deviation

$n=35$ sample size

$\mu_o =15$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

Part a State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less or equal than 15, the system of hypothesis would be:

Null hypothesis: $\mu \leq 15$

Alternative hypothesis: $\mu > 15$

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Part b Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{17-15}{\frac{4}{\sqrt{35}}}=2.958$

Part c P-value

The degrees of freedom are given by:

$df = n-1= 35-1=34$

Since is a right tailed test the p value would be:

$p_v =P(t_{34}>2.958)=0.0028$

Part d Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 15 at 1% of signficance.

7 0

3 years ago

How much do you pay for the house in total in the above example? Assume you will only be paying PMI for the first 2 years of the

Nataliya [291]

Answer:

start with your current mortgage balance. For a new mortgage, subtract your down payment from the home price. Calculate the LTV. Divide the loan amount by the property value.

Step-by-step explanation:

7 0

2 years ago

I need help with this problem?

Cerrena [4.2K]

Answer:

Step-by-step explanation:

Volume of cylinder:

$\boxed{\text{Volume of cylinder=$\pi r^{2}h$}}$

Bottom cylinder:

1 inch = 2.54 cm

diameter = 14 in

r = 14/2 = 7 in

r = 7 *2.54 = 17.78 cm

h = 4 in = 4*2.54 = 10.16 cm

Volume = 3* 17.78 * 17.78 * 10.16

= 9635.59 in³

Upper cylinder:

diameter = 12 in

r = 12/2 = 6in

r = 6*2.54 = 15.24 cm

h = 12 in = 12*2.54 = 30.48 cm

Volume = 3 * 15.24 *15.24 * 30.48

= 21237.63 in³

Volume of the object = 9635.59 + 21237.63

= 30873 cm³

3 0

2 years ago

What is the equation of the given circle?

azamat

Answer:

the last choice

Step-by-step explanation:

8 0

3 years ago

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