Twice a first number decreased by a second number is 22. The first number increased by four times the second number is

A company employs two shifts of workers. Each shift produces a type of gasket where the thickness is the critical dimension. The

Oksanka [162]

Answer:

a) $[-0.134,0.034]$

b) We are uncertain

c) It will change significantly

Step-by-step explanation:

a) Since the variances are unknown, we use the t-test with 95% confidence interval, that is the significance level = 1-0.05 = 0.025.

Since we assume that the variances are equal, we use the pooled variance given as

$s_p^2 = \frac{ (n_1 -1)s_1^2 + (n_2-1)s_2^2}{n_1+n_2-2}$ ,

where $n_1 = 40, n_2 = 30, s_1 = 0.16, s_2 = 0.19$ .

The mean difference $\mu_1 - \mu_2 = 10.85 - 10.90 = -0.05$ .

The confidence interval is

$(\mu_1 - \mu_2) \pm t_{n_1+n_2-2,\alpha/2} \sqrt{\frac{s_p^2}{n_1} + \frac{s_p^2}{n_2}} = (-0.05) \pm t_{68,0.025} \sqrt{\frac{0.03}{40} + \frac{0.03}{30}}$

$= -0.05\pm 1.995 \times 0.042 = -0.05 \pm 0.084 = [-0.134,0.034]$

b) With 95% confidence, we can say that it is possible that the gaskets from shift 2 are, on average, wider than the gaskets from shift 1, because the mean difference extends to the negative interval or that the gaskets from shift 1 are wider, because the confidence interval extends to the positive interval.

c) Increasing the sample sizes results in a smaller margin of error, which gives us a narrower confidence interval, thus giving us a good idea of what the true mean difference is.

6 0

4 years ago

60 minutes is 20% of ? minute s

Hatshy [7]

60 minutes is 20% of 300 minutes

3 0

3 years ago

Read 2 more answers

The length of a living room is 12 feet and its width is 1012 feet. The length of the room is being expanded by x feet. Choose an

Ivanshal [37]

Answer:

Option C. 10.5(12 + x) square feet

Option E. (126 + 10.5x) square feet

Step-by-step explanation:

step 1

Find the area of the original living room

we know that

The area of the original living room is equal to

$A=LW$

we have

$L=12\ ft\\W=10\frac{1}{2}\ ft=10.5\ ft$

substitute

$A=(12)(10.5)=126\ ft^2$

step 2

Find the new area of the living room

The length of the room is being expanded by x feet

so

we have

$L=(12+x)\ ft\\W=10.5\ ft$

The new area is

$A=10.5(12+x)\ ft^2$

The expanded form of the expression is

Apply distributive property

$A=10.5(12)+10.5(x)\\A=(126+10.5x)\ ft^2$

6 0

3 years ago

A number x is no more than 18. *write it as an inequality*

scZoUnD [109]

Answer:

x ≤ 18

Step-by-step explanation:

The ≤ symbol means "greater than or equal to". Since it is 'no more' than 18, that means it can be 18 or less. Thus, less than OR equal to. Hope I helped.

7 0

2 years ago

Together, Kyle and Tyler traveled 425 miles to the beach. If Kyle traveled 240 miles, how far did Tyler travel?

Papessa [141]

Answer:

185 miles

Step-by-step explanation:

We are given that

Both Kyle and Tyler traveled total distance to the beach=425 miles

Kyle traveled distance to the beach=240 miles.

We have to find the distance traveled by Tyler.

To find the distance traveled by Tyler we will subtract distance traveled by Kyle form total distance traveled by together Kyle and Tyler.

Let x be the distance traveled by Tyler.

According to question

$x+240=425$

$x=425-240=185$ miles

Hence, Tyler travels distance to the beach=185 miles

4 0

3 years ago

Read 2 more answers

Twice a first number decreased by a second number is 22. The first number increased by four times the second number is - 7.