Aresearcher for a paint company is measuring the level of a certain chemical contained in a certain type of paint. if the paint contains too much of this chemical, the quality of the paint will be compromised. on average, each can of paint contains 10 percent of the chemical. how many cans of paint should the sample contain if the researcher wants to be 98 percent certain of being within 1 percent of the true proportion of this chemical?

The sample should contain 4870 cans of paint.

Step-by-step explanation:

According to the given information , we have

The prior estimate of proportion=

Margin of error : E=0.01

Critical value for 98% confidence interval =

Formula to find the sample size :

i.e.

Hence, the sample should contain 4870 cans of paint.

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.