The weight of a shaft that is produced by a firm is normally distributed with a mean of 15 pounds. Determine the standard deviation of weight such that 99% of the shafts weighs less than 16.5 pounds. Assume a standard deviation of 0.55 for the shaft. If the firm wants 95% of the shafts it produces to weigh more than 14 pounds, what should be the mean weight for the shafts.

σ = 0.6438

= 14.902  pounds

Step-by-step explanation:

Given that:

The mean = 15

sample mean  = 16.5

At 99% C.I, the level of significance is = 1 - 0.99 = 0.01

By applying the central limit theorem;

σ = 0.6438

Assuming the S.D of the shaft = 0.55

At 95% confidence interval level, from the tables, the z value = -1.64

Using the central limit theorem

If we make the mean , the subject of the formula: we have:

= 14.902  pounds

d

step-by-step explanation:

hello and welcome!

so, when we see the words "proportional" along with a table, we need to know that we're looking numbers that divide by the same thing.

looking at this table, we simply have to do a trial and error, and divide to see which numbers have the same quotient. if you look at choice a & c, they both have equal quotients for three of the numbers, with one exception, so those can't be the answer. looking at b, there is no similarity, so that can't be it. then, we see d; if you divide all the numbers in the table, you'll see that they all divide by two, which is a proportional relationship, and our answer!

also, always remember that the x will always be the number that goes into y, and somewhere behind this table, is a formula. for this specific table, the formula would be:

since our x-value is being divided by two to get the y-value. and if they were to ask for more numbers in the series, this is the formula you would use to find them.

answer: 8d

step-by-step explanation:

45+5= 50+5=55+5=60