Please help me I need help

Evaluate 9!/6!3! plz helppp:)))

Helga [31]

Answer:

84 :-)

Step-by-step explanation:

5 0

3 years ago

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What is the surface are for this figure??

UkoKoshka [18]

Answer:

31.5

Step-by-step explanation:

You need to first use the formula of calculating surface area of a cuboid

SA=2(lw+lh+wh)

now you put the values in as

H=3

W=1.5

L=2.5

You get 31.5

Hope this Helps!

7 0

3 years ago

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What is a2+b2=c2 what formula is this Amos trevor_frost

Keith_Richards [23]

Answer:

$\huge{\boxed{\boxed{\tt { ⎆ \ Pythagorean \ Theorem :-}}}} \$

$a {}^{2} + b {}^{2} = c {}^{2}$

This is the formula for the pythagorean theorem i.e, one leg of a triangle squared plus another leg of a triangle squared equals the hypotenuse squared.

6 0

3 years ago

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5) In a certain supermarket, a sample of 60 customers who used a self-service checkout lane averaged 5.2 minutes of checkout tim

Ne4ueva [31]

Answer:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

$S_p=2.940$

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

$df=60+72-2=130$

$p_v =P(t_{130}$

Assuming a significance level of $\alpha=0.05$ we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane

Step-by-step explanation:

Data given

Our notation on this case :

$n_1 =60$ represent the sample size for people who used a self service

$n_2 =72$ represent the sample size for people who used a cashier

$\bar X_1 =5.2$ represent the sample mean for people who used a self service

$\bar X_2 =6.1$ represent the sample mean people who used a cashier

$s_1=3.1$ represent the sample standard deviation for people who used a self service

$s_2=2.8$ represent the sample standard deviation for people who used a cashier

Assumptions

When we have two independent samples from two normal distributions with equal variances we are assuming that

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

The statistic is given by:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2}}}$

And t follows a t distribution with $n_1+n_2 -2$ degrees of freedom and the pooled variance $S^2_p$ is given by this formula:

$\S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}$

System of hypothesis

Null hypothesis: $\mu_1 \geq \mu_2$

Alternative hypothesis: $\mu_1 < \mu_2$

This system is equivalent to:

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

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

We can find the pooled variance:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

And the deviation would be just the square root of the variance:

$S_p=2.940$

The statistic is given by:

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

The degrees of freedom are given by:

$df=60+72-2=130$

And now we can calculate the p value with:

$p_v =P(t_{130}$

Assuming a significance level of $\alpha=0.05$ we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane

5 0

3 years ago

On a mountain, the temperature decreases by 18°F every 5000 feet. What integer represents the change in temperature at 20,000 ft

attashe74 [19]

To find this answer, use multiples. For every 5000 feet ascended, deduct 18 degrees. For 20,000 feet, which is (4 * 5000), use (4 * -18). In this case, the answer is -72 degrees F, so the integer described would be -72.

7 0

3 years ago