PLEASE HELP 20 POINTS PLEASE HELP BROOO

An envelope contain 40 shopping vounchers of which 25 voucher each have value of $50 and 15 vouchers each have a value of $100.

Ghella [55]

Answer:

yes is correct ◆◆◆◆◆◆◆◆◆◆♡♡♡♡♡

7 0

3 years ago

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A water tank in the shape of an inverted circular cone has a base radius of 3 m and height of 7 m . If water is being pumped int

Wittaler [7]

The water level increases by 0.608 meters per minute when the water is 3.5 m deep

<h3>How to determine the rate?</h3>

The given parameters are:

Radius, r = 3
Height, h = 7
Rate in, V' = 4.3m^3/min

The relationship between the radius and height is:

r/h = 3/7

Make r the subject

r = 3h/7

The volume of a cone is;

$V = \frac 13\pi r^2h$

This gives

$V = \frac 13\pi (\frac{3h}{7})^2h$

Expand

$V = \frac{3h^3}{49}\pi$

Differentiate

$V' = \frac{9h^2}{49}\pi h'$

Make h' the subject

$h' = \frac{49}{9\pi h^2}V'$

When the water level is 3.5.

We have:

$h' = \frac{49}{9\pi * 3.5^2}V'$

Also, we have:

V' = 4.3

So, the equation becomes

$h' = \frac{49}{9\pi * 3.5^2} * 4.3$

Evaluate the products

$h' = \frac{210.7}{346.36}$

Evaluate the quotient

h' = 0.608

Hence, the water level increases by 0.608 meters per minute

Read more about volumes at:

brainly.com/question/10373132

#SPJ1

7 0

2 years ago

An ice sculpture is melting from the heat. it's height changes by -2/25 every hour, what will it be after 5 hours?

madreJ [45]

Answer:

Height will have changed by -2/5

Step-by-step explanation:

change in height = (change in height/hour) × hours

= (-2/25) × 5 = -2/5

7 0

3 years ago

Kensington City Cafe recently introduced a new flavor of coffee. They served 28 grande cups

Dmitrij [34]

Answer:

jumbo 23 oz, grande 16 oz

Step-by-step explanation:

Use g for grande and j for jumbo

The first equation: 28g + 33j = 1207

The second equation: 28g + 53j = 1667

Subtract the first from the second

28g + 53j = 1667

- 28g + 33j = 1207

Equal 20j = 460

j = 23

Put 23 in for j in either equation and solve for g:

28g + 33(23) = 1207

28g + 759 = 1207

28g = 448

g = 16

5 0

2 years ago

A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies. Random

Yuliya22 [10]

Answer:

b) independent samples t-test

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

$p_v =2*P(t_{8}>0.154) =0.881$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 (boys) is NOT significantly different than the mean for the group 2 (Girls).

Step-by-step explanation:

The system of hypothesis on this case are:

Null hypothesis: $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

Or equivalently:

Null hypothesis: $\mu_1 - \mu_2 = 0$

Alternative hypothesis: $\mu_1 -\mu_2\neq 0$

Our notation on this case :

$n_1 =5$ represent the sample size for group 1

$n_2 =5$ represent the sample size for group 2

We can calculate the mean and deviation for eaach group with the following formulas:

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

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

$\bar X_1 =5.92$ represent the sample mean for the group 1

$\bar X_2 =5.74$ represent the sample mean for the group 2

$s_1=1.88$ represent the sample standard deviation for group 1

$s_2=1.81$ represent the sample standard deviation for group 2

If we see the alternative hypothesis we see that we are conducting a bilateral test and with independnet samples t test.

b) independent samples t-test

The statistic is given by this formula:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{\sqrt{\frac{s^2_1}{n_1}}+\frac{S^2_2}{n_2}}$

And now we can calculate the statistic:

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

The degrees of freedom are given by:

$df=5+5-2=8$

And now we can calculate the p value using the altenative hypothesis:

$p_v =2*P(t_{8}>0.154) =0.881$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 (boys) is NOT significantly different than the mean for the group 2 (Girls).

7 0

3 years ago