Alexa Alexa brought 32 apples for $4.16 at the rate what 1 Apple cost

"4. A coffee manufacturer is interested in whether the mean daily consumption of regular-coffee drinkers is less than that of de

SSSSS [86.1K]

Answer:

With a 0.01 significance level and samples of 50 and 40 cofee drinkers, there is enough statistical evidence to state that the mean daily consumption of regular-coffee drinkers is less than that of decaffeinated-coffee drinkers.

The test is a one-tailed test.

Step-by-step explanation:

To solve this problem, we run a hypothesis test about the difference of population means.

$$$Sample mean $\bar X: \bar X=4.35$\\Sample mean $\bar Y: \bar Y=5.84$\\Population variance $\sigma^2_X: \sigma^2_X=1.2^2$\\Population variance $\sigma^2_Y: \sigma^2_Y=1.36^2$\\Sample size $n_X=50$\\Sample size $n_Y=40$\\Significance level $\alpha=0.01$\\Z criticals values (for a 0.01 significance)\\(Left tail test) Z_{1-\alpha}=Z_{0.990}=-2.32635\\($Right tail test) Z_{\alpha}=Z_{0.010}=2.32636\\($Two-tailed test) $Z_{1-\alpha/2}=Z_{0.995}=-2.57583$ and $ Z_{\alpha/2}=Z_{0.005}=2.57583\\\\$

The appropriate hypothesis system for this situation is:

$H_0: \mu_X-\mu_Y=0\\H_a: \mu_X-\mu_Y \leq 0\\\\$

Difference of means in the null hypothesis is:

$\mu_X - \mu_Y = M_0=0\\\\$

$$$The test statistic is$ Z=\frac{( \bar X-\bar Y)-M_0}{\sqrt{\frac{\sigma^2_X}{n_X}+\frac{\sigma^2_Y}{n_Y}}}\\$ $$$The calculated statistic is Z_c=\frac{[(4.35-5.84)-0]}{\sqrt{\frac{1.20^2}{50}+\frac{1.36^2}{40}}}=-5.43926\\p-value = P(Z \leq Z_c)=0.0000\\\\$

Since, the calculated statistic $Z_c$ is less than critical $Z_{1-\alpha}$ , the null hypothesis should be rejected. There is enough statistical evidence to state that the mean daily consumption of regular-coffee drinkers is less than that of decaffeinated-coffee drinkers.

7 0

4 years ago

Read 2 more answers

Which fits according to the chart?

Scilla [17]

3x+y=16 because it adds 3 each time so 13+3=16

5 0

3 years ago

There are 884 students enrolled at a certain college. The number of students from Indiana is exactly three times the number of s

AnnyKZ [126]

Answer:

Let the no. Of students from Indiana be x

Let the no. Of students from the rest of the country and abroad be y

x = 3y (Given) (i)

x + y = 884 (Given) (ii)

Subtract equation (ii) from 1

x -3y = 0

-(x+y = 884)

-4y = -884

Therefore y = 221

Therefore no. Of students from the rest of the country and abroad is 221

Substituting the value of y in (i)

x = 3 x 221

Therefore x = 663

Therefore no. Of students from Indiana is 663

Hope this helps!

5 0

4 years ago

The table below represents a function. ху 011 25 5 26 750 Which equation makes the table true? x) = 2x + 1 Rx) = x² + 1 fx) = 2x

garri49 [273]

Answer: 3rd

Step-by-step explanation:

4 0

4 years ago

What are the two equations to set up to solve the equation |2x−3|=11 ?

Lorico [155]

your answer is going to be:

2x−3=11 and 2x−3=−11

Step-by-step explanation: 100% sure

5 0

4 years ago

Alexa Alexa brought 32 apples for $4.16 at the rate what 1 Apple cost​

Alexa Alexa brought 32 apples for $4.16 at the rate what 1 Apple cost