Answer:
= 403
Step-by-step explanation:
the sum to n terms of an arithmetic series is
=
(a + l) ← a is the first term and l the last term
here a = - 5 and l = 67 , then
=
(- 5 + 67) = 6.5 × 62 = 403
Answer:
No, there is not sufficient evidence to support the claim that the bags are underfilled
Step-by-step explanation:
A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 434 gram setting.
This means that the null hypothesis is:

It is believed that the machine is underfilling the bags.
This means that the alternate hypothesis is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
434 is tested at the null hypothesis:
This means that 
A 9 bag sample had a mean of 431 grams with a variance of 144.
This means that 
Value of the test-statistic:



P-value of the test:
The pvalue of the test is the pvalue of z = -0.75, which is 0.2266
0.2266 > 0.01, which means that there is not sufficient evidence to support the claim that the bags are underfilled.
Answer:
7t
Step-by-step explanation:

Answer:
The sample size is 
Step-by-step explanation:
From the question we are told that
The sample standard deviation is 
The mean difference of the two groups is 
The standard error is 
=> 
Let assume that the confidence level is 95% hence the level of significance is

=> 
So the critical value of
obtained from the normal distribution table is

Generally the margin of error is mathematically evaluated as

Generally the sample size is mathematically represented as
![n =[ \frac{Z_{\frac{\alpha }{2} * s^2}}{E}]^2](https://tex.z-dn.net/?f=n%20%3D%5B%20%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%20%2A%20s%5E2%7D%7D%7BE%7D%5D%5E2)
=> ![n = [\frac{1.96 * 1.5}{0.49} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%5B%5Cfrac%7B1.96%20%2A%201.5%7D%7B0.49%7D%20%5D%5E2)
=> 