Suppose you want an 85 percent confidence level. What value would you use to multiply the standard error of the mean by?

One-tailed test = 1.04

Two-tailed test (42.5% each way) = 1.44

These values were found by looking in a table in the back of a stat text called something like "areas under the normal distribution."

1.44

To determine the value to multiply the standard error of the mean by in order to achieve an 85 percent confidence level, we need to refer to the critical value for the desired confidence level.

For a confidence level of 85 percent, we subtract it from 100 to get the corresponding alpha value: 100% - 85% = 15%.

Next, we divide this alpha value by 2 (since we want a two-tailed test) to get the alpha value for each tail: 15% / 2 = 7.5%.

Finally, we convert this alpha value for each tail into a z-score using a standard normal distribution table or a statistical software. The z-score represents the number of standard deviations from the mean.

Let's assume that using a standard normal distribution table, the z-score for a 7.5% tail area is approximately 1.44.

Therefore, the value to multiply the standard error of the mean by to achieve an 85 percent confidence level would be approximately 1.44.

To determine the value to multiply the standard error of the mean by for a given confidence level, you need to refer to the z-table. The z-table is a statistical tool that provides critical values for different levels of confidence.

To find the value for an 85 percent confidence level, you need to determine the corresponding z-value. Start by subtracting the desired confidence level from 100 percent to get the complement. In this case, the complement would be 100% - 85% = 15%.

Next, divide the complement by 2 to get the two-tailed probability. Therefore, 15% / 2 = 7.5%.

Now, you need to find the z-value that corresponds to the 7.5% probability in the cumulative distribution function (CDF) of the standard normal distribution. The CDF gives you the probability of getting a value less than or equal to a specific z-value.

Using a z-table or a statistical software, you can look up the z-value corresponding to the 7.5% probability. In this case, the z-value would be approximately 1.44.

Finally, you can multiply the z-value by the standard error of the mean to obtain the desired value.